Punctuation, when it matters.
Not a full style guide — the short list of marks that trip professional copy. The comma splice that looks harmless. The apostrophe in it's that inverts the meaning. The hyphen that makes well-written paper different from well written paper.
Comma
No comma splice
The bar was crowded, we left.The bar was crowded, so we left.Why A comma cannot join two independent clauses. Use a conjunction (and, but, so), a semicolon, or a period.
Note Accepted in dialogue and deliberate style; avoid in expository prose.
Oxford comma for clarity
I'd like to thank my parents, Ayn Rand and God.I'd like to thank my parents, Ayn Rand, and God.Why The serial comma before the final "and" prevents the last two items from being read as an appositive of the first.
Note AP style omits it; Chicago, Oxford, and most book publishing use it. Be consistent.
No comma before a restrictive clause
The employees, who arrived late, were fired.The employees who arrived late were fired.Why Without commas: only the late employees were fired. With commas: all the employees were fired, and they happened to be late. The comma is not decorative — it changes meaning.
Note "Which" usually takes commas (non-restrictive); "who/that" takes them only when the clause is parenthetical.
Comma before a coordinating conjunction joining clauses
She read the brief and she signed it.She read the brief, and she signed it.Why When two independent clauses are joined by for, and, nor, but, or, yet, so — the "FANBOYS" — a comma goes before the conjunction.
Note Drop the comma if the clauses are short and closely linked: "She read it and signed."
Comma after an introductory phrase
After the meeting we went home.After the meeting, we went home.Why An introductory phrase or clause of more than a few words takes a comma to separate it from the main clause.
Note Short introductions can skip the comma: "Today we ship."
Comma for direct address
Let's eat grandma.Let's eat, grandma.Why When addressing someone directly, a comma separates the name from the rest of the sentence. Without it, grandma becomes the meal — the canonical punctuation meme for a reason.
Note Also applies to titles and endearments: "Yes, sir." "Goodbye, Moira."
Commas around an appositive
My sister Alice lives in Berlin.My sister, Alice, lives in Berlin.Why If you have exactly one sister, "Alice" is extra information — the commas mark that off. If you have two sisters, "Alice" identifies which one, and the commas should go.
Note The comma test is semantic, not decorative: commas mean "non-essential."
Commas in dates
January 1 2026 was a Thursday.January 1, 2026, was a Thursday.Why Both commas are required in US style — one before and one after the year. Leaving out the second comma is the more common error.
Note UK dates ("1 January 2026") take no comma — the different order removes the ambiguity.
Commas around a state or country
She works in Austin, Texas as a chef.She works in Austin, Texas, as a chef.Why The state or country acts as an appositive — bracket it with commas on both sides. The missing second comma is one of the most common US newspaper errors.
Note Same rule for "Paris, France, is humid in August."
Comma between coordinate adjectives
It was a long tiresome drive.It was a long, tiresome drive.Why Two adjectives both modifying the noun independently take a comma. Test: could you reverse them or insert "and"? If yes, use a comma ("tiresome, long drive" works → "long, tiresome drive").
Note Cumulative adjectives don't: "a big red ball" — not "a big, red ball" — because "red ball" is a unit that "big" then modifies.
Commas around an interruption
The result however was unexpected.The result, however, was unexpected.Why Parenthetical words like "however," "therefore," "for example," "in fact" take commas on both sides when inserted mid-sentence.
Note At the start of a sentence they take only a trailing comma: "However, the result was unexpected."
No comma before "too" at sentence end
She wanted to come, too.She wanted to come too.Why Modern style drops the comma before a sentence-final "too." Older guides kept it; Chicago and most current style guides don't.
Note Mid-sentence "too" still takes commas if it's parenthetical: "She, too, was hungry."
Comma after an introductory dependent clause
Because she was tired she went to bed.Because she was tired, she went to bed.Why A dependent clause that starts a sentence takes a comma. Flip the order and the comma disappears: "She went to bed because she was tired."
Note The rule is position, not punctuation: when the dependent is first, the comma is needed.
Comma before "too" — optional, governs emphasis
I went too.I went, too.Why A comma before "too" or "either" signals a slight pause and softens emphasis. Without it, the sentence reads more as an afterthought. Both are acceptable — use it where the pause helps.
Note House styles vary. The Chicago Manual of Style leaves it optional; some publications require it.
No comma between subject and verb
The girl with the long red hair, walked into the room.The girl with the long red hair walked into the room.Why A single comma between a subject and its verb breaks the clause. Paired commas around an interrupter are fine; a lone one is not.
Note The error is most common with long subject phrases, where writers pause to breathe and reach for a comma by reflex.
No comma inside a compound predicate
She opened the box, and gasped.She opened the box and gasped.Why One subject with two verbs is a compound predicate, not a compound sentence. No comma before the conjunction.
Note Two subjects + two verbs ("She opened the box, and he gasped") takes a comma — that is a compound sentence.
Use commas around "etc.," "i.e.," "e.g."
She packed apples, oranges etc into the bag.She packed apples, oranges, etc., into the bag.Why Latin abbreviations take a preceding comma to end the list, and a trailing comma if the sentence continues. "Etc." in particular still needs its full stop.
Note Chicago now permits no comma after i.e. and e.g.; most publishers still keep it.
No comma before "as well as" when restrictive
Rain, as well as snow, is forecast.Rain as well as snow is forecast.Why If "as well as" adds an essential element, omit the commas. Parenthetical use ("The CEO, as well as the board, attended") keeps them.
Note The verb stays singular — "as well as" does not form a compound subject with "and."
Modern style drops commas around Jr., Sr., III
Martin Luther King, Jr., delivered the speech.Martin Luther King Jr. delivered the speech.Why AP and Chicago both shifted to no-comma around 2000. The person's own usage is canonical; follow it if known.
Note Reverting to the older comma-pair is not wrong — just out of date.
Comma before a quoted sentence
She said "I am ready".She said, "I am ready."Why When a quotation is a full sentence, introduce it with a comma. Short fragments woven into the sentence need no comma — "she called it 'fine'."
Note Colons introduce longer or formal quotations; commas handle ordinary speech.
No commas around "either...or" or "neither...nor"
Neither the coach, nor the team, was ready.Neither the coach nor the team was ready.Why Correlative conjunctions (either/or, neither/nor, not only/but also) bind two items; commas break the binding.
Note Verb agrees with the nearer subject: "Neither the boys nor the teacher was present" (but it reads awkwardly — rewrite if you can).
Commas around "however" as interjection
The plan however was flawed.The plan, however, was flawed.Why "However" as a conjunctive adverb is parenthetical — set off by commas when it interrupts a clause, and by a following comma when it opens one.
Note When it means "in whatever way," no commas: "However you slice it, the number is wrong."
Comma after a sentence-opening adverb
Fortunately the building was empty.Fortunately, the building was empty.Why Sentence adverbs (Fortunately, Clearly, Indeed, Obviously) comment on the whole sentence. A comma marks them as parenthetical rather than as a regular adverb modifying the verb.
Note Optional for very short openers ("Then we left"); standard for sentence-scope adverbs.
Comma between an "if" clause and the main clause when "if" leads
If it rains we will cancel.If it rains, we will cancel.Why A leading dependent clause is set off by a comma. Flip the order — "We will cancel if it rains" — and the comma drops.
Note Same rule for "when," "while," "because," "although" openings.
Comma after a leading "although," "though," "even though"
Although we were tired we kept walking.Although we were tired, we kept walking.Why Concessive clauses are dependent: when they open the sentence, they take a following comma. When they trail, no comma unless the clause is plainly parenthetical.
Note "We kept walking, although we were tired" reads as afterthought; "We kept walking although we were tired" reads as restrictive. Both are correct; the comma changes emphasis.
Comma for the elided verb in parallel clauses
He chose apples; she oranges.He chose apples; she, oranges.Why When the verb is omitted in the second clause, a comma marks the omission. Chicago calls this the "comma of ellipsis."
Note Common in formal prose and old sermons; rare in casual writing, but still correct.
Comma after a yes/no reply
Yes I will come.Yes, I will come.Why "Yes" and "no" at sentence start are interjections. A comma separates them from the clause that follows.
Note Applies to "oh," "well," "hey," and similar openers too.
Comma before a tag question
You're coming aren't you?You're coming, aren't you?Why The tag ("aren't you?") is a grammatically separate clause checking the statement. A comma marks the pivot.
Note Applies to "right?", "isn't it?", "don't you think?" at sentence end.
Comma after "oh" as an interjection
Oh that's lovely.Oh, that's lovely.Why "Oh" opens a thought; the comma lets the reader pause before the content.
Note When "oh" is emphatic and short, an exclamation ("Oh!") can replace the comma.
Comma after "well" as a discourse marker
Well I suppose so.Well, I suppose so.Why "Well" here is a pragmatic marker, not an adverb. The comma signals the register shift.
Note In formal writing, "well" can often be dropped entirely.
Commas around "i.e." and "e.g."
Citrus fruits e.g. lemons and limes are sour.Citrus fruits, e.g., lemons and limes, are sour.Why In US style, both commas flank the abbreviation. British style often drops the comma after, but the lead-in comma always stays.
Note Chicago recommends replacing them with English: "that is" and "for example" read better in running prose.
Comma after an introductory participial phrase
Walking home I saw the comet.Walking home, I saw the comet.Why A participial phrase ("walking home") describes the subject; the comma prevents a misread ("I saw the comet walking home").
Note Without the comma, a dangling modifier can sneak in.
Comma after the year in a month-day-year date
On October 14, 1066 the Normans won.On October 14, 1066, the Normans won.Why The year completes the date; a second comma closes the parenthetical and returns to the main clause.
Note Day-month-year form (14 October 1066) needs no internal commas.
Commas around post-nominal degrees and honorifics
Jane Doe Ph.D. will present.Jane Doe, Ph.D., will present.Why "Ph.D." is a non-restrictive clarifier; two commas flank it like any appositive.
Note Chicago has dropped the commas in some recent guidance; AP keeps them.
Comma every three digits from the right in large numbers
10000 attended. 1000000 viewers.10,000 attended. 1,000,000 viewers.Why English convention groups digits in threes with commas (Indian English uses 10,00,000 for a million). The separator aids legibility.
Note Scientific and technical writing sometimes uses thin spaces instead (10 000).
Comma between units in a compound measurement
He is 5 feet 9 inches tall.He is 5 feet, 9 inches tall.Why Two compound units need separation; the comma reads like "and." Some style guides allow the hyphen form "5-foot-9."
Note In strictly numeric contexts (5'9") no comma is needed.
Comma before "but" when contrasting two things
Not rain but snow.Not rain, but snow.Why The "not X, but Y" construction is parallel; the comma marks the inversion.
Note Some editors drop the comma for tight phrasing; the meaning is unchanged.
Comma between quoted speech and the attribution tag
"Run" she said."Run," she said.Why The comma sits inside the closing quotation mark in US style; the attribution (she said) is a separate clause.
Note A question mark or exclamation replaces the comma: "Run!" she said.
Comma after a sentence-opening transitional adverb
Moreover we left early.Moreover, we left early.Why Transitional words (moreover, therefore, furthermore, meanwhile) need a comma at sentence start to mark the pivot.
Note In mid-sentence, two commas flank them: "We, therefore, left."
Comma after a long introductory phrase
After the long and difficult meeting finally ended we went home.After the long and difficult meeting finally ended, we went home.Why An introductory clause of more than four words typically gets a comma — the reader needs a pause to find the main clause.
Note For very short intros ("At dawn we left"), the comma is optional.
Commas around a state or country name following a city
He moved to Paris France in 2010.He moved to Paris, France, in 2010.Why The pair of commas treats "France" as a clarifier — essentially an appositive.
Note When the place is a single word (e.g., "Geneva"), no comma follows.
No comma before an essential "that" clause
The book, that I bought yesterday, is red.The book that I bought yesterday is red.Why "That" introduces essential (restrictive) information — it identifies which book. Commas would signal non-essential, which it isn't.
Note "Which" clauses are often non-essential and take commas; "that" clauses do not.
AP style omits the Oxford comma
News style: red, white, and blue.News style: red, white and blue.Why Associated Press style drops the final series comma; Chicago, Oxford, and most book publishers keep it. Pick one per publication.
Note When omission creates ambiguity ("I'd like to thank my parents, Ayn Rand and God"), reinstate the comma.
Comma after a letter or email closing
Sincerely JaneSincerely, JaneWhy "Sincerely," "Regards," "Yours truly," and similar always take a comma before the signature.
Note The signature itself takes no punctuation; a period after the name looks overbearing.
Comma after "Dear [Name]" in an informal letter
Dear Mom How are you?Dear Mom, How are you?Why In letters to friends or family, a comma after the greeting is informal and warm. Business letters use a colon ("Dear Mr. Smith:").
Note Emails split the difference — a comma is standard even for semi-formal messages.
Commas around a mid-quote attribution
"I'm fine" she said "thanks.""I'm fine," she said, "thanks."Why A mid-quote attribution is parenthetical; two commas flank "she said" and the second half of the quote continues lowercase.
Note If the next portion is a new sentence, capitalise it and use a period before "she said."
Comma after "Too" or "Also" at sentence start
Too many cooks however ruin the broth.Too many cooks, however, ruin the broth.Why A sentence adverb ("however") needs two commas when it interrupts — at start, middle, or end.
Note "Too" as an intensifier at the start rarely takes a comma: "Too many people showed up."
No comma between month and year alone
October, 1066 was decisive.October 1066 was decisive.Why Comma is only needed with a day: "14 October 1066" (no commas) or "October 14, 1066" (comma after day).
Note Some legal and older publishing styles kept the comma; modern style drops it.
Commas around a name in direct address with interjection
Oh Nilesh please check this.Oh, Nilesh, please check this.Why Two commas: one after the interjection, one before the main clause. "Nilesh" is a vocative — always flanked.
Note Missing the second comma is the classic "Let's eat Grandma" error.
Comma before "so" when it joins two independent clauses
The shop was closed so we left.The shop was closed, so we left.Why "So" as a conjunction joining two main clauses is like "and" or "but" — it needs a comma in front.
Note If "so" means "in order to," no comma: "I ran so I could catch the train."
Commas around a non-restrictive "which" clause
My car which I bought last year is blue.My car, which I bought last year, is blue.Why The clause adds information but doesn't identify "which car" — the writer has only one. Two commas treat it as parenthetical.
Note If you could drop the clause without losing the meaning, it needs commas.
Semicolon
Semicolons join related independent clauses
She read the brief, she signed it.She read the brief; she signed it.Why A semicolon joins two complete sentences closely related in thought, without a conjunction. Both sides must be able to stand alone.
Note If you can't drop a period there, don't use a semicolon either.
Semicolons in complex lists
The panel included John Ray, the chairman, Maria Diaz, the CFO, and Li Wen, the counsel.The panel included John Ray, the chairman; Maria Diaz, the CFO; and Li Wen, the counsel.Why When list items themselves contain commas, semicolons do the outer separating — otherwise the reader can't tell where one item ends.
Note This is the one case where a semicolon legitimately replaces a comma.
Semicolon ≠ colon
We need three things; focus, time, and trust.We need three things: focus, time, and trust.Why A colon introduces a list or amplification. A semicolon does not. They are not interchangeable.
Note If you're pointing forward to something, reach for the colon.
Semicolon before a conjunctive adverb
She finished the manuscript, however, she wasn't happy with it.She finished the manuscript; however, she wasn't happy with it.Why Words like "however," "therefore," "moreover," "consequently" joining independent clauses take a semicolon before them and a comma after.
Note This is a classic comma-splice trigger — commas alone can't carry this weight.
Don't pile semicolons
She walked; she ran; she stopped; she laughed.She walked. She ran. She stopped. She laughed.Why More than one or two semicolons in a paragraph starts to feel like a mannered stammer. If every clause could be its own sentence, make them sentences.
Note The semicolon should signal a specific relation, not just "another sentence coming."
Fix a comma splice with a semicolon
It was late, we left anyway.It was late; we left anyway.Why Two independent clauses joined only by a comma form a "comma splice" — a classic error. A semicolon, period, or coordinating conjunction ("and," "but") fixes it.
Note Novelists get away with comma splices for rhythm. In non-fiction prose, the semicolon is the safer fix.
Semicolon before "therefore," "thus," "moreover"
We lost the vote, therefore, we left.We lost the vote; therefore, we left.Why Conjunctive adverbs (therefore, thus, moreover, hence, furthermore, consequently) do not join independent clauses on their own — they need a semicolon in front.
Note A comma follows the adverb when a pause there reads naturally; omit it if the flow is quick.
Lowercase after a semicolon
The lights dimmed; The show began.The lights dimmed; the show began.Why A semicolon signals continuation, not a new sentence. Only capitalise after one if the first word is a proper noun.
Note Periods and question marks end sentences; semicolons keep them running.
No semicolon with a coordinating conjunction
The fog was thick; but we drove on.The fog was thick, but we drove on.Why If you already have "and," "but," "or," "nor," "so," "for," or "yet," a comma is enough. The semicolon replaces the conjunction; it does not accompany it.
Note Exception: very long clauses with internal punctuation can take semicolon + conjunction for clarity. Use sparingly.
Semicolon before "namely," "for example," "that is"
Only one person fits the role, namely Ari.Only one person fits the role; namely, Ari.Why When "namely," "that is," or "for example" introduces an appositive, a semicolon (or em dash) marks the break cleanly. A comma alone can read as a list boundary.
Note Chicago permits comma + namely for short appositives; semicolon is clearer when the appositive is itself clause-length.
Semicolons between items in a series containing commas
The delegates came from Paris, France, Austin, Texas, and Tokyo, Japan.The delegates came from Paris, France; Austin, Texas; and Tokyo, Japan.Why When individual list items already contain commas, switch to semicolons for the item separators. Otherwise the reader cannot see where each item ends.
Note Chicago is explicit on this; AP accepts it reluctantly and prefers rewriting.
Semicolon before a conjunctive adverb with a second independent clause
The bridge was out, therefore, we took the long route.The bridge was out; therefore, we took the long route.Why "Therefore," "however," "moreover," "consequently" linking two main clauses take a semicolon before, comma after.
Note A period and a new sentence is equally correct and often cleaner.
No space before a semicolon, one space after
She knew the risks ;she signed anyway.She knew the risks; she signed anyway.Why English typography never puts a space before a semicolon. French conventions differ (space before), which trips bilingual writers.
Note Word processors may auto-add the space from French autocorrect — disable if it appears.
Both sides of a semicolon must be independent clauses
Because it rained; we cancelled the picnic.Because it rained, we cancelled the picnic.Why A semicolon joins two sentences that could stand alone. "Because it rained" cannot — it's a dependent clause needing only a comma.
Note If the first half is a fragment, use a comma; if it's a complete sentence, a semicolon or period.
Use a semicolon to balance parallel independent clauses
Some like tea, others like coffee.Some like tea; others like coffee.Why Two short, balanced clauses read best with a semicolon — it signals the contrast more strongly than a comma splice and more economically than a period.
Note This is the "sophisticated comma splice" that editors permit.
Semicolon outside a closing quotation mark (US and UK)
He said, "I'm done;" she said nothing.He said, "I'm done"; she said nothing.Why Unlike commas and periods (which go inside in US style), semicolons always sit outside the closing quotation mark.
Note The same rule applies to colons.
Never use a semicolon after a greeting
Dear Dr Smith; I am writing to...Dear Dr Smith, I am writing to...Why Greetings take a comma (informal) or colon (formal business). A semicolon here is simply wrong.
Note German letter conventions use a semicolon; English never does.
Semicolons can chain three or more independent clauses
I came, I saw, I conquered.I came; I saw; I conquered.Why For maximum emphasis on each act, semicolons separate the trio into standalone pronouncements. The comma-only version (accurate to Caesar) is also correct but lighter.
Note Chicago manual allows commas in very short triplets; semicolons are the formal default.
Semicolon vs em-dash: pick one per tone
She knocked; but nobody answered — the house was empty.She knocked; nobody answered. The house was empty.Why Semicolons are formal; em-dashes are casual. Mixing both in one sentence muddles the register.
Note Pick the semicolon for essays and reports; pick the em-dash for blogs and creative writing.
Apostrophe
"It's" is a contraction; "its" is possessive
The dog wagged it's tail.The dog wagged its tail.Why "It's" = "it is" or "it has." "Its" = belonging to it. Possessive pronouns — his, hers, ours, its — never take an apostrophe.
Note Substitute "it is" in your head. If the sentence breaks, the apostrophe is wrong.
No apostrophe in a plural
The Smith's live here. CD's on sale.The Smiths live here. CDs on sale.Why An apostrophe does not pluralise. "The Smith's" means "belonging to one Smith." Greengrocer's apostrophes — "apple's 50c" — are the classic offender.
Note Exception: some style guides allow apostrophes for single-letter plurals ("dot your i's") to avoid reading as "is."
Possessive of a singular ending in -s
James' car. The boss' office.James's car. The boss's office.Why For most singular nouns ending in -s, add 's, not just '. "The dress's hem," not "the dress' hem." This is Chicago, MLA, and plain modern usage.
Note AP style uses the apostrophe alone ("James' car"). Historical or classical names sometimes drop the final s: "Moses' laws," "Jesus' teachings."
Plural possessive: -s'
The employee's meeting was moved.The employees' meeting was moved.Why If the group already ends in -s, the apostrophe goes after the -s. "Employee's" = one employee's; "employees'" = the employees' collectively.
Note Irregular plurals follow the singular rule: "the children's playground."
No apostrophe in a decade
Music of the 1980's. Fashion in the 90's.Music of the 1980s. Fashion in the '90s.Why The -s pluralises the year. No possession, no apostrophe. If you want to abbreviate to two digits, the apostrophe goes before the year ("'90s"), not after.
Note "1980's music" is fine — possessive of the decade. "1980s music" is also fine — "1980s" used attributively.
"Your" vs "you're"
Your the best.You're the best.Why "You're" = "you are." "Your" = belonging to you. Substitute "you are" to test.
Note The single most-flagged error on social media grammar policing.
"Whose" vs "who's"
Who's turn is it?Whose turn is it?Why "Who's" = "who is" or "who has." "Whose" = belonging to whom. Same substitution test as "your/you're."
Note "Whose" is one of the few possessives that looks wrong because most possessives end in 's.
Joint vs separate possession
Jim's and Pam's wedding was beautiful.Jim and Pam's wedding was beautiful.Why If two people share one thing, only the second name takes the apostrophe. If each has their own, both names do: "Jim's and Pam's offices."
Note The grammar encodes ownership structure. Joint ownership, joint apostrophe.
Apostrophe on plural lowercase letters
Mind your ps and qs.Mind your p's and q's.Why Lowercase single letters get an apostrophe in the plural to prevent misreading ("ps" could be read as the abbreviation).
Note Capital letters generally do not: three As, four Bs. MLA keeps the apostrophe for both; Chicago drops it on capitals.
Apostrophe stands in for omitted letters in contractions
Didnt see that coming.Didn't see that coming.Why The apostrophe marks omission (o in "not," i in "is," u in "you"). Dropping it is a mistake, not a style choice.
Note Texting and chat platforms often auto-correct missing apostrophes; edited prose always keeps them.
Plural surnames take -s, not -'s
Welcome to the Smith's house.Welcome to the Smiths' house. (or, if informal) Welcome to the Smiths'.Why Plural surnames get plain -s (the Smiths); the possessive sits outside the plural (the Smiths'). An apostrophe on a plain plural is the "grocer's apostrophe."
Note Surnames ending in s, x, z, ch, sh pluralise with -es: the Joneses, the Foxes, the Churches.
Singular nouns ending in s: add 's
James' phoneJames's phoneWhy Chicago, MLA, and most modern stylebooks prefer 's on singulars ending in s. AP still allows a bare apostrophe for proper names.
Note Ancient names and set phrases keep the bare apostrophe: "Jesus' disciples," "for goodness' sake," "in Moses' name."
Double possessive is standard English
(misguided "correction") a friend of mine → a friend of mea friend of mine; a friend of John'sWhy The "of + possessive" construction is idiomatic. "A friend of John" and "a friend of John's" both exist; the second is the more natural.
Note Some older style books object; every modern usage guide defends the double possessive.
Inanimate objects can take the possessive 's
(overcorrection) the cover of the book → mandatory "of"the book's cover, the day's agenda, the company's policyWhy English allows possessive 's freely on inanimate nouns. The idea that only people can possess is a prescriptivist myth.
Note Choose between "the book's cover" and "the cover of the book" for rhythm — both are correct.
Singular names ending in s take 's (US) or just ' (UK)
Charles book was missing.Charles's book was missing. (UK: Charles' book was missing.)Why US Chicago style adds 's to singular possessives regardless: Dickens's, Jones's, Moses's. British style often drops the final s for classical names.
Note AP style drops the second s for proper names: Charles'.
Possessive pronouns never take an apostrophe
That book is her's. The cat lost it's collar.That book is hers. The cat lost its collar.Why His, hers, its, ours, yours, theirs — all possessive pronouns. An apostrophe would signal a contraction, not possession.
Note "It's" is only the contraction of "it is" or "it has."
Apostrophe in "o'clock" marks the dropped "of the"
See you at 5 oclock.See you at 5 o'clock.Why "O'clock" is a contraction of "of the clock" (Middle English). The apostrophe stands for the missing letters.
Note Never "oclock," "o-clock," or "oclock." The apostrophe is permanent.
Apostrophe before an abbreviated year
The summer of 89 was hot. Class of 2026's party.The summer of '89 was hot. The class of '26 gathered.Why The apostrophe marks the dropped century digits: 2026 → '26, 1989 → '89. It faces right (as a closing quote) in most fonts.
Note Word processors often auto-convert to a left-facing mark (‘); correct it to right-facing (’).
Two apostrophes in "rock 'n' roll"
rock n roll. rock 'n roll.rock 'n' roll.Why Both the opening and closing letters of "and" are dropped, so two apostrophes replace them.
Note AP now also accepts "rock and roll" (spelled out) in running text.
"Till" is not a shortening — "'til" with an apostrophe is
I'll wait til next week. I'll wait till 9.I'll wait until next week. I'll wait till 9.Why "Till" is a standalone word, not a shortening of "until" — it predates "until" by centuries. If you do contract, use 'til.
Note Chicago recommends "till" as the neutral short form; "'til" is more informal.
Apostrophe marks the dropped "d" in "ma'am"
Thank you maam. Mam, the taxi is here.Thank you, ma'am.Why "Ma'am" is a contraction of "madam" — the apostrophe replaces the "da."
Note Regional variants: "mum" (UK affection), "mam" (northern UK / Ireland) — different words, not the same contraction.
Apostrophe marks dropped letters in contracted verbs
I am runnin late. Were goin to the store.I am runnin' late. We're goin' to the store.Why In informal spelling, the apostrophe replaces the dropped "g" (or other letters). Without it, the reader loses the cue that a contraction is intended.
Note In edited prose, spell the word in full: "I'm running late."
Apostrophe for plurals of single letters to avoid confusion
Mind your ps and qs. Straight As.Mind your p's and q's. Straight A's.Why Plural of a single letter takes 's for clarity — "as" and "is" would become confusing words otherwise.
Note Plurals of multi-letter acronyms do not: CDs, MBAs, URLs.
Italicise the title, add 's after: the possessive of a book or film
Hamlets soliloquy is famous.Hamlet's soliloquy is famous.Why Titles take possessive 's like any singular noun: Hamlet's, Macbeth's, Ulysses's (US) or Ulysses' (UK).
Note In italic running text, the 's is roman (not italic): *Ulysses*'s.
Apostrophe 's after an abbreviation behaves like any noun
The CEOs decision. The USAs position.The CEO's decision. The USA's position.Why Acronyms and initialisms take possessive 's just like common nouns — no special rule.
Note For plural + possessive: "the CEOs' decisions" (multiple CEOs, plural possessive).
Closing single quote (’) is the correct apostrophe shape
The ‘ 90s were strange.The ’90s were strange.Why Typographically, the apostrophe is a closing single quotation mark (’), not an opening one (‘). Word processors sometimes flip it at word start.
Note For 'tis, 'em, and similar elisions, always use the closing form (’).
Apostrophe for plural time possessives
Two weeks notice. A days delay.Two weeks' notice. A day's delay.Why Time phrases act as possessives of duration — the "weeks" or "day" possess the "notice" or "delay." Singular duration: 's. Plural duration: s'.
Note Common in letters and legal writing; still confuses fluent writers.
Apostrophe on the last word of a compound possessive
My sister's-in-law house. My father's-in-law house.My sister-in-law's house. My father-in-law's house.Why The apostrophe-s attaches to the full compound — treat the whole unit as one noun.
Note Plural: "sisters-in-law." Plural possessive: "sisters-in-law's."
Proof "its" and "it's" by substitution: "it is"
Its been raining since dawn.It's been raining since dawn.Why If you can replace the word with "it is" or "it has," it takes the apostrophe. If not, it's a possessive and doesn't.
Note The substitution rule is foolproof; use it every time you hesitate.
Dashes & hyphens
Em dash for a sharp break
The decision-taken under pressure-surprised everyone.The decision — taken under pressure — surprised everyone.Why The em dash (—) marks a parenthetical aside or a sharp interruption. Use spaces around it in UK/Oxford style; no spaces in US/Chicago style. Either is correct — be consistent within a piece.
Note Two commas, two parentheses, or two em dashes all work here. The dashes are the most emphatic.
En dash for ranges
Open 9-5 weekdays. pages 23-47.Open 9–5 weekdays. Pages 23–47.Why The en dash (–) signals a range ("from X to Y") or a connection between two things ("the London–Paris train"). The hyphen (-) only joins compound words.
Note In running prose, "from 9 to 5" is often clearer than "9–5" anyway.
Hyphen for compound modifiers
A well written paper. A state of the art model.A well-written paper. A state-of-the-art model.Why When two or more words act as a single modifier before a noun, hyphenate them. "A state-of-the-art model" — the hyphens bundle the phrase so the reader knows where it ends.
Note Drop the hyphens after the noun: "The model is state of the art." No confusion, no hyphen.
No hyphen after an -ly adverb
A carefully-planned project.A carefully planned project.Why Adverbs ending in -ly don't need a hyphen to connect to the following participle — the -ly already signals it modifies the adjective. Hyphens bundle words that could otherwise be mistaken for separate modifiers.
Note Non-ly adverbs do take a hyphen: "a well-planned project," "a much-loved author."
Suspensive hyphen in compound modifiers
A two and three bedroom apartment.A two- and three-bedroom apartment.Why When two hyphenated compounds share a base, a "suspensive" hyphen keeps the first one attached to the missing word.
Note Also: "short- and long-term effects." "Pre- and post-surgery visits."
Minus sign is not a hyphen
A loss of -15% year-over-year.A loss of −15% year-over-year.Why The proper minus sign (U+2212, −) is subtly wider than a hyphen-minus. In mathematical or financial writing, use the real minus where precision matters.
Note For news prose the hyphen-minus is fine; for tables and equations, the real minus aligns better.
Hyphens in compound-modifier ages
A five year old child.A five-year-old child.Why Compound modifiers joining a number, a unit, and an adjective take hyphens before the noun. Without the hyphens the phrase fragments visually.
Note After the noun, drop them: "The child is five years old."
Hyphenate compound adjectives before a noun
A well known author.A well-known author.Why When two words together modify a noun that follows them, they take a hyphen. After the noun, the hyphen drops: "The author is well known."
Note Doesn't apply when the first word is an -ly adverb: "a highly paid consultant," not "highly-paid."
Em dashes take no spaces (US style)
He left the room — slowly — and closed the door.He left the room—slowly—and closed the door.Why Chicago, AP, and most US publishers set em dashes closed, no space. UK practice often uses a spaced en dash instead.
Note Whichever you choose, be consistent across the document.
En dash in compound modifiers with an open element
The New York-London flightThe New York–London flightWhy When one half of the compound already contains a space ("New York"), a hyphen is too tight. The en dash signals the connection across a longer element.
Note Also used in "a pre–Civil War letter," "a World War II–era tank."
Hyphenate prefixes for proper nouns or ambiguity
reenter, antiAmerican, recover (to cover again)re-enter, anti-American, re-cover (to cover again; contrast recover = regain)Why English closes most prefix + root compounds (antimatter, prewar). Hyphenate before a proper noun, before a repeated vowel if unclear, or to distinguish homographs.
Note Chicago leans further toward closed forms each edition; AP keeps more hyphens.
Hyphenate compound numbers 21 through 99
Thirty five thousand dollarsThirty-five thousand dollarsWhy English hyphenates two-word cardinal numbers 21–99 when spelled out. "Hundred," "thousand," "million" do not take a hyphen with the number in front.
Note Fractions used as modifiers also take a hyphen: "a two-thirds majority." As nouns, they don't: "two thirds of the committee."
Suspended hyphen for paired compounds
State owned and operated facilitiesState-owned and -operated facilitiesWhy When two compounds share a modifier, hang the second hyphen to show the shared element.
Note Common patterns: "first- and second-class tickets," "pre- and post-war," "short- and long-term."
Hyphenate fractions used as modifiers
A two thirds majorityA two-thirds majorityWhy When a fraction modifies a noun, hyphenate it. When it functions as a noun itself ("two thirds of the voters"), no hyphen.
Note "One-half" and "one-third" take hyphens as modifiers; "a half" and "a third" as standalone nouns usually do not.
Hyphen in double-barrelled surnames
Helena Bonham Carter-Smith (if her name is hyphenated)Helena Bonham-Carter (hyphenated) vs Helena Bonham Carter (open)Why A hyphen makes a double-barrelled name a single surname; without it, the last two names are kept as unhyphenated compound. Follow the person's own form.
Note Bonham Carter (open) and Day-Lewis (hyphenated) are both correct for the actors who use them.
Em dash before a pulled-out attribution
To be, or not to be. ShakespeareTo be, or not to be. — ShakespeareWhy In quotes set off from the text (pull quotes, epigraphs), an em dash precedes the attribution. No name: no quote.
Note Book design often uses a short rule instead of an em dash; both are acceptable.
Em dash (—) sets off a clause; en dash (–) connects a range
The 2020-2024 report—the one you requested-is attached.The 2020–2024 report — the one you requested — is attached.Why En dash for number or date ranges; em dash for parenthetical asides. They're different marks with different jobs.
Note Mac: Opt+hyphen gives en; Opt+Shift+hyphen gives em. Windows: Alt+0150 / Alt+0151.
Em dash for interrupted dialogue
"I was about to say...—" she broke off."I was about to say—" she broke off.Why When a speaker is interrupted, use an em dash at the cut-off. An ellipsis signals trailing-off, not interruption.
Note The em dash stays inside the closing quotation mark.
En dash between two proper nouns functioning as a compound adjective
The Boston-Chicago route. Pre-World War II diplomacy.The Boston–Chicago route. Pre–World War II diplomacy.Why An en dash indicates a connection between equal-weight proper nouns — it's visually cleaner than a hyphen for multi-word names.
Note With single-word proper nouns, many publications still use a hyphen (Boston-Chicago).
En dash in sports scores and win-loss records
India beat Sri Lanka 275-230. The Lakers finished 54-28.India beat Sri Lanka 275–230. The Lakers finished 54–28.Why Scores are ranges (from-to); the en dash is correct. Hyphens work in headlines where typography is informal.
Note Tennis scores use a hyphen (6-4 6-3) by convention.
Hyphenate "co-" before a proper noun or to avoid ambiguity
coowner, coAmerican, co-star (of a film)co-owner, co-American, costar (of a film).Why Most "co-" compounds close up today (cosponsor, costar). Hyphenate before a doubled vowel (co-owner) or a proper noun (co-American).
Note Chicago closes more aggressively each edition; AP still hyphenates co-author.
"Ex-" as former always takes a hyphen
expresident, exhusband, exsoldierex-president, ex-husband, ex-soldierWhy When "ex-" means "former," a hyphen separates it from the noun. Solid compounds confuse with Latin "ex" (out of).
Note "Extraordinary" is not an exception — that "ex-" isn't a separable prefix.
Hyphenate each "great-" in ancestral compounds
Greatgrandfather. Great great grandmother.Great-grandfather. Great-great-grandmother.Why Each generation adds a "great-" with a hyphen; the chain signals how far back.
Note "Grandfather" and "grandmother" themselves are closed; only "great-" is hyphenated.
"Half-" compounds: mostly hyphenated, some closed
Halfhearted (closed), halfbaked (closed).Halfhearted. Half-baked.Why Some half-compounds have closed up (halfhearted, halftime); others stay hyphenated (half-baked, half-hour, half-life).
Note Dictionaries differ; pick one and be consistent.
"Self-" compounds always take a hyphen
selfesteem, selfaware, selfrighteousself-esteem, self-aware, self-righteousWhy Unlike most prefixes, "self-" is always hyphenated before its noun or adjective.
Note Exception: "selfless" and "selfsame" are closed (the "self-" is no longer a separable prefix).
Hyphen between a capital letter and a following noun
Tshirt, Xray, Uturn, LShapedT-shirt, X-ray, U-turn, L-shapedWhy A letter-noun compound retains the hyphen for legibility — "Tshirt" reads as a typo.
Note The letter stays capitalised; the following word stays lowercase (except at sentence start).
Hyphenate age compounds before a noun
A ten year old girl. A three year old car.A ten-year-old girl. A three-year-old car.Why When the age modifies a noun, all three parts are hyphenated. As a noun itself ("a ten-year-old"), hyphens remain.
Note After the noun, no hyphens: "She is ten years old."
Hyphenate spelled-out compound numbers from 21 to 99
Twenty one, ninety nine, one hundred and five.Twenty-one, ninety-nine, one hundred and five.Why Compound cardinal and ordinal numbers between 21 and 99 always take a hyphen. Higher compounds don't.
Note Fractions when spelled out also take a hyphen: "two-thirds," "three-quarters."
Hyphenate a participle in an adjectival compound before a noun
A fast growing company. A well intentioned plan.A fast-growing company. A well-intentioned plan.Why Before the noun, the compound needs a hyphen for clarity. After the noun, the hyphen often drops: "the plan was well intentioned."
Note "-ly" adverb + participle usually skips the hyphen: "a hotly contested vote."
Street name compounds use hyphens in formal address
Park View Avenue, River side RoadPark-View Avenue. Riverside Road.Why Multi-word street name compounds are often hyphenated (especially in older British usage). Modern usage tends to close them.
Note Follow local postal conventions; Indian Post and USPS have their own rules.
En dash replaces "to" in ranges, not both
From 9–5. Between 2010–2015.From 9 to 5. 9–5. Between 2010 and 2015.Why If you start with "from," finish with "to," not a dash. Similarly for "between" + "and." The en dash is the dash-only shorthand.
Note Mixing the two constructions is a style error; editors always catch it.
Spaces around em dash (UK) or no spaces (US)
UK: She arrived—late—with apologies. US: She arrived — late — with apologies.UK: She arrived — late — with apologies. US: She arrived—late—with apologies.Why US Chicago style closes up em dashes (no space); UK and Oxford style opens them up (with thin or full spaces). Both are correct — pick one and stay.
Note The New York Times uses no spaces; The Guardian uses spaces. House style decides.
Suspended hyphen omits the second word in a series
Both short-term and long-term goals are defined.Both short- and long-term goals are defined.Why When two compound adjectives share a second word, a suspended hyphen marks the omission. The shared word appears once at the end.
Note Common in technical and editorial writing; avoid in casual prose.
"Non-" compounds: generally closed, hyphenated before proper nouns
Non fiction, non-smoker, nonAmericanNonfiction, nonsmoker, non-American.Why AP and Chicago close up most "non-" compounds. Hyphenate only before a proper noun or an initial vowel where clarity suffers.
Note The hyphen was standard until the 1990s; modern style drops it.
Em dash (or colon) introduces a bulleted list after a lead-in
The plan includes; speed, cost, quality.The plan includes — speed, cost, quality.Why A colon or em dash introduces a list; semicolons don't. The em dash feels more casual; the colon is the formal default.
Note In running prose, rephrasing often reads cleaner: "The plan includes speed, cost, and quality."
Colon
What precedes a colon should stand alone
My favourite writers are: Didion, Orwell, and Sontag.My favourite writers are Didion, Orwell, and Sontag.Why A colon follows an independent clause. "My favourite writers are" is not a complete sentence — no colon. Either drop the colon or finish the clause first ("The list is short: Didion, Orwell, and Sontag").
Note Chicago insists on a full clause before a colon. AP is looser. If in doubt, drop the colon.
Capitalisation after a colon
One rule holds: Finish the sentence before the colon.One rule holds: finish the sentence before the colon.Why In US style, lowercase after a colon unless what follows is a proper noun, a quotation, or two or more complete sentences. UK style is similar. Don't reflex-capitalise.
Note Exception: "One rule holds: Finish the sentence. Then add the colon." — two full sentences, so cap the first.
Colon to introduce a formal quotation
She paused, then said, "We are done."She paused, then announced: "We are done."Why A comma introduces casual or direct speech; a colon introduces a formal or emphatic one. The colon also marks a stronger pause.
Note Use only when the introduction is a complete clause.
Colon for ratios
A ratio of 2 to 1.A ratio of 2:1.Why In mathematical or technical writing, a colon separates the two quantities in a ratio. No spaces around it.
Note Same convention for time ("10:30"), biblical verses ("John 3:16"), and score lines ("3:2").
Colon between title and subtitle
Moby Dick — Or, The Whale.Moby Dick: Or, The Whale.Why Book titles conventionally use a colon to separate the main title from the subtitle. A dash can work informally; the colon is the publishing-industry default.
Note Some presses capitalise the first word after the colon (Chicago). Others don't (AP). Pick one.
Colon between hours and minutes (US)
We met at 10.30 a.m.10:30 a.m. (US) / 10.30 a.m. (UK, traditional)Why US English uses a colon; traditional UK style uses a point. Digital contexts — ISO timestamps, durations — use a colon everywhere.
Note The 24-hour form "22:15" is colon-only.
Colon after a formal US business salutation
Dear Mr. Smith,\n\nI write to...Dear Mr. Smith:\n\nI write to...Why US business letters traditionally use a colon after the salutation; US personal letters and UK letters use a comma.
Note In email, practice has drifted toward the comma everywhere; the colon still reads formal.
Colon between book chapter and verse
John 3, 16John 3:16Why The colon separates chapter from verse in biblical and Quranic citation. Ranges within a verse use an en dash: "Matthew 5:3–12."
Note Shakespeare citations use the same pattern — "Hamlet 3:1" means Act 3, Scene 1 (some editors prefer Roman: III.i).
Colon to introduce a climactic word or phrase
There was only one thing left to do — run.There was only one thing left to do: run.Why When the short element after the introduction is the point of the sentence, a colon brings it into focus. The em dash is the more casual alternative.
Note Capitalisation of the word after the colon: Chicago lowercase unless a full sentence follows.
Colon in script-style dialogue tags
ANNA, "I'm leaving."ANNA: I'm leaving.Why In screenplay and script format, a colon (sometimes followed by a line break) sets the speaker's line. No quotation marks are needed; the format does the work.
Note In interview transcripts the same convention holds: Q: What did you see? A: Nothing.
Colon introduces a vertical bulleted or numbered list
You will need; - bread - butterYou will need: - bread - butterWhy A colon is the standard lead-in for a list set out below; semicolons belong between list items only inside a running sentence.
Note If the introductory line is not a complete sentence, avoid the colon.
No colon after "such as," "including," or "for example"
Citrus fruits such as: lemons, limes, and oranges.Citrus fruits such as lemons, limes, and oranges.Why These words already introduce the list — a colon is redundant and incorrect. Let the prose flow.
Note "The following" or "these" is the cue that a colon is appropriate.
Colon introduces warnings and notices
Warning Do not operate machinery.Warning: Do not operate machinery.Why "Warning," "Note," "Caution," and similar labels are followed by a colon, then the full sentence. The next word is capitalised.
Note This pattern is standard on product labels, road signs, and technical writing.
Colon separates title from subtitle
War and Peace - a novel of RussiaWar and Peace: A Novel of RussiaWhy In publishing convention, a colon separates the main title from the subtitle. Both parts are capitalised in title case.
Note A dash can replace the colon in informal article titles, but not in book catalogue entries.
Colon after a speaker's name in dramatic scripts
JULIET - O Romeo, Romeo!JULIET: O Romeo, Romeo!Why Play scripts and screenplays use a colon after the (usually all-caps) speaker name. The dialogue begins on the same line or the next.
Note Film scripts traditionally put the speaker name centred with no colon; stage plays use the colon form.
Colon between hours and minutes in time
5.30 AM. 21.45 hours.5:30 AM. 21:45 hours.Why US and international conventions use a colon; British English sometimes uses a full stop (5.30 p.m.). Both are valid; mix them and editors complain.
Note Digital clocks and ISO 8601 always use the colon form.
Colon after the URL protocol (https, mailto)
https//example.com, mailto example.comhttps://example.com, mailto:example@example.comWhy Technical convention: scheme name + colon + slashes (for http/https/ftp) or scheme + colon + address (mailto, tel).
Note This is not a style choice — URIs are defined by RFC 3986; the colon is structural.
Colon after "Subject:", "Re:", "To:"
Subject - Q2 Results. RE Progress.Subject: Q2 Results. Re: Progress.Why Email and memo headers follow field-name + colon + space + value. Dashes or spaces alone look sloppy.
Note "Fwd:", "Cc:", "Bcc:" — all follow the same colon pattern.
One colon per sentence — avoid stacking
The answer is clear: there are three options: run, stay, or wait.The answer is clear. There are three options: run, stay, or wait.Why Two colons in one sentence read as a jumble. Split into two sentences or reshape the prose.
Note If a quotation already contains a colon, punctuate the sentence around it differently.
Colon for formal introduction, em dash for casual
Three rules — always, sometimes, never.Three rules: always, sometimes, never.Why Both marks can introduce what follows. Colon reads formal; em dash reads conversational. Match to the document register.
Note Business reports use the colon; blog posts often use the em dash.
Quotation marks
Commas and periods inside quotes (US)
He said "yes", then left.He said "yes," then left.Why In US style, commas and periods always go inside closing quotation marks, regardless of whether they belong to the quoted material. UK style places them based on logic.
Note This is arbitrary. US writers who insist on logical placement ("yes", then) are fighting their own style guides.
Semicolons and colons outside quotes
She called it "progress;" others disagreed.She called it "progress"; others disagreed.Why Semicolons and colons always go outside the closing quotation mark, even in US style. Exception to the "everything inside" rule.
Note Universal across US and UK style — one of the few areas they agree on.
Question mark inside or outside?
Did she say "yes?"Did she say "yes"?Why The question mark goes where the question ends. If the whole sentence is a question but the quoted part isn't, the mark goes outside.
Note If the quote is the question: She asked, "Are you ready?" Mark inside.
Nested quotes alternate
She said, "I read "Hamlet" last year."She said, "I read 'Hamlet' last year."Why US style: outer quotes are double, inner are single. UK style is often the reverse (outer single, inner double). Either way, alternate to avoid two of the same.
Note For further nesting, go back to doubles: "'He said "yes"'" — rare, but valid.
Long quotes are indented, not quoted
"The weather has been strange all summer. The heat starts in April now..."(set the passage as an indented block with no quote marks)Why Block quotations — Chicago's threshold is roughly 100 words or five lines — are set off by indentation. Adding quotation marks is redundant.
Note Thresholds vary by style: MLA uses four typed lines; Chicago uses five; APA uses 40 words.
UK uses single quotes as primary; US uses double
(US draft) He said 'yes.'(US) He said "yes." / (UK) He said 'yes.'Why British style sets primary speech in single quotes and nested quotes in double. American style reverses the nesting. Pick one and hold.
Note Newspapers and online publications are drifting; watch the style sheet you're writing for.
Scare quotes mark distance from the word
The "new" menu has the old "dishes."The new menu has the old dishes. (drop quotes unless irony is intended)Why Scare quotes flag a word the writer is using without endorsing. Overuse reads as sarcasm or irony that wasn't wanted.
Note One pair per paragraph at most. If everything is in quotes, nothing is.
Short-work titles in quotes; long-work titles in italics
He read "The Great Gatsby" on the plane.He read *The Great Gatsby* on the plane.Why Book, album, film, play, and journal titles are italicised. Songs, short stories, poems, and episodes are in quotation marks.
Note Chapter titles within books take quotes; article titles within journals take quotes.
New speaker, new paragraph
"Hello," said Anna. "Hi," Ben replied."Hello," said Anna.\n\n"Hi," Ben replied.Why Each change of speaker begins on a new line. Running speakers together costs the reader a beat guessing who spoke last.
Note A single paragraph can contain one speaker's dialogue plus their action — but not two speakers.
No quotation marks on indirect speech
He said that "he would be late."He said that he would be late.Why Indirect discourse reports the content of speech without reproducing the exact words. Quotes belong only on the verbatim form.
Note Summary or paraphrase inside quotes is a common journalistic error; edit it out.
UK style places the comma outside the closing quotation mark when the comma is not part of the quote
UK: "That's right," she said. US: "That's right", she said.UK: "That's right", she said. US: "That's right," she said.Why US style always places commas and periods inside; UK (logical) style only if they belong to the quoted matter.
Note Mixing the two styles within one piece marks it as unedited.
US double quotes primary, single nested; UK reversed
US: 'She said "hi",' he reported. UK: "She said 'hi'," he reported.US: "She said 'hi,'" he reported. UK: 'She said "hi",' he reported.Why Primary marks enclose the outer quotation; nested marks enclose the inner. US flips them from the UK convention.
Note Both conventions are internally consistent — pick one per publication.
Curly (smart) quotes in prose; straight quotes in code
prose with "straight" quotes. Code with "smart" quotes.Prose with "smart" quotes. Code with "straight" quotes.Why Typography: curly (“” ‘’) for prose; straight (" ') for code, config files, and anywhere a parser is involved.
Note Word processors auto-convert; text editors don't. Know which you're using.
Multi-paragraph quotations open each paragraph but close only the last
"First paragraph." "Second paragraph.""First paragraph. "Second paragraph."Why Classic fiction convention: opening marks every paragraph signal continuity; the closing mark appears only when the quote ends.
Note Modern typesetting often uses a block quote instead, which eliminates the convention.
Ellipsis inside quotes marks words removed from the original
"We the people... establish this Constitution.""We the people [...] establish this Constitution."Why Chicago recommends bracketed ellipsis for clarity — readers know you chose to cut, not that the author used ellipsis.
Note MLA and AP allow unbracketed ellipsis; check the style guide.
Italicise foreign-language quotations; translate in roman
He said carpe diem which means seize the day.He said *carpe diem* — "seize the day."Why Italics flag the foreign text; roman (upright) marks the translation as yours. Quotation marks optionally surround the translation.
Note Common foreign words (cliché, ad hoc) are not italicised; obscure ones are.
Scare quotes mark irony or distance, never emphasis
Our "organic" tomatoes are the "freshest" you'll find.Our organic tomatoes are the freshest you'll find.Why Quotation marks around normal words read as sarcasm — they question the claim. For emphasis, use italics or bold.
Note Market signage often breaks this rule accidentally, creating the opposite effect.
Quotations over ~40 words set as a block, indented, no quote marks
"This is a long passage [500 words] — all inside quote marks — through to the end."Block-indent the passage without quote marks. Cite after the last word.Why Block quotations don't need the visual cue of marks — the indentation does the work. Chicago and MLA specify ~40 words; APA, ~40.
Note Nested quotes inside a block take double marks in US style, single in UK.
Quote marks around titles of short works (songs, poems, articles)
I heard "Bohemian Rhapsody" on the radio. (Wait — this is correct!)I heard "Bohemian Rhapsody" on the radio.Why Songs, poems, short stories, essays, articles, episodes — all go in quote marks. Books, albums, films, series go in italics.
Note A double-rule: the rule is container vs. contained. Container (album) italic, song inside quotes.
Italicise unspoken thought; quote marks are for speech
"Why would he do that?" she thought.*Why would he do that?* she thought.Why Modern fiction uses italics for thought to distinguish it from dialogue. Quote marks for thought now read dated.
Note Some contemporary authors drop italics too and rely on attribution alone.
No comma before a partial quotation that flows into the sentence
She described him as, "a walking contradiction."She described him as "a walking contradiction."Why When the quote completes the syntax of the surrounding sentence (as here, as the object of "as"), no comma is needed.
Note A comma is only needed when the quote would otherwise form a complete sentence on its own.
Retain the source language's quote marks inside a translation
The French original used «guillemets» but we changed them to "quotes" anyway.The French original used «guillemets»; in the translated passage we use "quotes."Why When citing foreign text verbatim, retain the original marks (« », „“, 「」) to preserve the quotation's visual authenticity.
Note In a translated passage itself, switch to the target language's marks.
New paragraph each time a different speaker speaks
"I agree." "I don't." "Why not?" (all on one line)"I agree." "I don't." "Why not?"Why Fiction convention: each speaker gets their own paragraph. This makes dialogue visually scannable without repeated attribution.
Note The first speech in a scene usually includes attribution; subsequent lines may not need it.
Ellipsis
Ellipsis is three dots, not four
She paused.... Then she spoke.She paused... Then she spoke.Why An ellipsis is exactly three dots (…). Four dots appear only when an ellipsis ends a sentence — the fourth is the period.
Note Style guides vary on spacing: Chicago uses spaces ( . . . ); most modern style omits them.
Ellipsis marks omission, not hesitation
She... didn't... know.She paused. "I don't know."Why In formal writing, an ellipsis signals that words have been omitted from a quotation. For hesitation in fiction, em dashes or explicit description usually work better.
Note Overuse of ellipses in casual writing reads as melodramatic. A single ellipsis is almost always enough.
Trailing ellipsis in dialogue
She whispered, "I thought...."She whispered, "I thought..."Why When a sentence trails off mid-thought, three dots signal the incompleteness. Four dots (including a period) imply the sentence is actually finished.
Note Dialogue in fiction tolerates heavier ellipsis use than exposition. But even there, less is more.
Four dots when the omission ends a sentence
The plan is simple...it must succeed.The plan is simple.... It must succeed.Why If omission falls at the end of a sentence, keep the terminal period, then the three-dot ellipsis. The first dot is the period; the next three are the ellipsis.
Note Chicago differs: Chicago puts the period after the ellipsis when a new sentence follows.
Spaces around and between the dots (Chicago)
The witnesses...remained silent.The witnesses . . . remained silent.Why Chicago sets three dots with spaces between, and a space on each side of the whole ellipsis. AP and most web style close it up.
Note Unicode … (a single glyph) is acceptable in most contexts; academic style often requires the spaced form.
Bracketed ellipsis for omissions you introduce
He wrote, "the project failed... for lack of funds."He wrote, "the project failed [...] for lack of funds."Why In scholarly quotation, bracket ellipses distinguish editorial omission from ellipses the original author used.
Note If the source is ellipsis-free, unbracketed ellipses are fine; brackets clarify only when the source also uses them.
No ellipsis at the very start of a quotation
She said, "... we must leave."She said, "We must leave." (or, if the opening must be flagged) "[W]e must leave."Why Quoting from mid-sentence, you begin with a capital or a bracketed capital. Ellipsis at the head of a quote is untidy and usually unnecessary.
Note Chicago §13.50. Flag the omission only if the reader would otherwise misread the intent.
Ellipsis for a trailing-off, em dash for an interruption
"I was about to...—" (ellipsis plus em dash)"I was about to..." (trail-off) OR "I was about to—" (cut off)Why Trailing off (fading) uses ellipsis; being interrupted (sharp cut) uses em dash. Don't combine them.
Note A common failure in edited dialogue — pick one per break.
No ellipsis at the end of a quoted sentence if the rest is not the writer's cut
"The end..." (when the original ended on a period)"The end."Why Ellipsis at quote end should signal omitted text — if the original stopped there, don't add one.
Note If the writer is trailing off (narrative, not quoted), ellipsis is natural.
Chicago spaces each dot; Unicode … is not acceptable in Chicago
Chicago: "the road... was long." (solid glyph)Chicago: "the road . . . was long." (three spaced dots)Why Chicago prefers three periods with spaces between them (. . .) for typographic balance. AP permits the Unicode glyph (…).
Note Some copy-editors type ". . . " and insert non-breaking spaces to prevent line breaks between dots.
Avoid ellipsis as a lazy substitute for "etc." in a list
We sell shirts, hats, socks...We sell shirts, hats, socks, and more.Why An ellipsis at list end reads as trailing off — it implies the writer gave up. A specific close (and more, and so on) is cleaner.
Note In bullet lists, the ellipsis is particularly jarring.
Three dots for a mid-sentence omission; four dots for an end-of-sentence omission
"We the people [...] establish this Constitution.""We the people . . . establish this Constitution."Why Three dots signal words cut mid-sentence; four dots (the sentence-end period plus three ellipsis dots) signal omission at sentence end.
Note MLA and Chicago differ on bracketing; be explicit in your style guide.
Brackets & parens
Period inside parens — sometimes
It was a long day. (The longest).It was a long day. (The longest.)Why If the parenthetical is a complete sentence outside another sentence, the period goes inside. If it's inside another sentence, the outer sentence's period goes outside.
Note "It was a long day (the longest)." — mid-sentence, no period inside.
Square brackets for your own words in a quote
He said "(she) wasn't happy."He said "[she] wasn't happy."Why Square brackets mark editorial additions to a quoted text — a pronoun clarification, a changed tense, or a "[sic]" flag.
Note Parentheses inside a quote belong to the original speaker. Brackets belong to you.
[sic] flags an error preserved from the source
The memo read, "their going to be late."The memo read, "their [sic] going to be late."Why Latin "thus" — flagged in brackets to signal the error is in the original, not the writer's. Italicise sic; do not repeat for multiple errors in the same quotation.
Note Use sparingly. A careful rewrite is often preferable to rubbing the quoted author's nose in the error.
Square brackets mark editorial additions inside a quote
He said, "the book (on taxation) is on the table."He said, "the book [on taxation] is on the table."Why Words you add to a quoted passage for clarity go in brackets, not parentheses — parentheses suggest the author wrote them.
Note Use brackets to change capitalisation, add an antecedent, or gloss a pronoun: "[T]he answer was [Henry's]."
Square brackets around a translation of a foreign-language quotation
She said, "Cogito, ergo sum (I think, therefore I am)."She said, "Cogito, ergo sum [I think, therefore I am]."Why A translation you supply is an editorial addition. Brackets mark it; parentheses would suggest the speaker supplied both forms.
Note Single quotes for the translation are a common alternative: "cogito, ergo sum" ('I think, therefore I am').
Square brackets inside parentheses
(see Smith (2019), p. 14)(see Smith [2019], p. 14)Why Nested parentheses become brackets in British and academic style. US style sometimes tolerates ((nested)) but brackets are always safer.
Note For three levels of nesting, descend through (brackets, parens, braces) — rare outside logic and maths.
Square brackets inside a quotation mark an editorial insertion
She said, "He (the CEO) resigned yesterday."She said, "He [the CEO] resigned yesterday."Why Parentheses inside a quote look like they're part of the speaker's words. Brackets signal "the writer added this for clarity."
Note A common academic convention; newspapers often skip it for brevity.
Brackets around "emphasis mine" or "emphasis added" in quotations
"This is *critical* to success." (with no annotation)"This is *critical* to success" [emphasis added].Why When a writer italicises a quote for emphasis, ethical writing flags the intervention. "[Emphasis added]" or "[emphasis mine]" is standard.
Note If the original already had italics, note "[emphasis in original]" instead.
Brackets replace a pronoun with its antecedent for clarity
Churchill said: "We shall fight them on the beaches." (Who is "them"?)Churchill said: "We shall fight [the Nazis] on the beaches."Why When a pulled quote lacks context, the brackets let the writer substitute a noun for the original pronoun without misquoting.
Note Over-use becomes paraphrase — consider quoting more context instead.
Parentheses for in-text citation, brackets for a numbered reference
(1) vs [Smith 2019] (inverted)(Smith 2019) vs [1]Why Author-date style uses parentheses; numbered reference style uses brackets. Consistency within a paper is essential.
Note APA uses parentheses; Vancouver uses brackets; IEEE uses brackets. Pick one upstream.
Brackets around a changed letter of case in a quotation
The report opens: "the committee finds..." (original: "The committee finds")The report opens: "[t]he committee finds..."Why When a quote is dropped mid-sentence and the original begins with a capital, brackets around the lowercased letter signal the editorial change.
Note MLA requires the brackets; Chicago now permits either silent change or brackets depending on formality.
Running a longer piece past the checker?
Paste a paragraph in — it flags the comma splices, misused apostrophes, and typical slips in one pass.