English, spelled differently everywhere.

Note Canada keeps -our despite its American neighbour; the convention is a deliberate identity marker. Exception: the political party is "Labor" in Australia (a deliberate US-style spelling chosen in 1912) but "labour" the word.

Note Oxford University Press uses -ize ("Oxford spelling"). The UN, EU, and most UK newspapers use -ise. Canada follows the US. Australia follows the UK. "Analyse" is always -se in UK/AU — the etymology is Greek *analusis*, not a Latin -ize verb.

Note "Meter" vs "metre" in UK: "metre" is the unit of length; "meter" is a measuring device (parking meter, gas meter). The distinction disappears in the US, where "meter" covers both.

Note Even in American English, only "catalog" and "analog" reliably shed the -ue; "dialogue," "monologue," "prologue" keep it. The rule is weaker than the others in this list.

Note The US rule is more logical — it mirrors the stress — but Commonwealth English treats the doubling as an orthographic convention regardless. When stress IS on the final syllable, everyone doubles: "controlled," "forgetting."

Note Canada sides with the US on most medical terms. Even UK usage is shifting — the BMJ style guide began accepting "fetus" over "foetus" in 2021, arguing that the Greek root never had -oe- in the first place.

Note The UK pattern: "a driving licence" (noun, -ce) but "to license a driver" (verb, -se). US and Canada-for-some-of-these collapse to one form. The distinction is a genuine style tell when reading international English.

Note Canada and Australia mostly align with the US on "program" regardless of sense. The UK is the outlier. The "computer program" exception in UK usage dates to the 1960s — imported American technical usage that stuck.

Note Most UK newspapers now use "jail." "Gaol" survives in older statutes, official documents, and literary prose — but it's a conscious stylistic choice today, not a live standard.

Note "Whisky" vs "whiskey": in practice, Scotch and Canadian are "whisky"; Irish and American are "whiskey." The distinction is distilled, not national. "Storey" vs "story": UK distinguishes a floor of a building (storey) from a tale (story); US writes "story" for both.

Note Unlike "-ise/-ize" where Oxford defends -ize, no one seriously defends -yze in UK usage — the Greek -lusis never had a -z. The US spelling is a Webster-era simplification by analogy with "-ize."

Note "Sulfur" is the IUPAC-approved spelling globally since 1990 — even UK chemistry journals now use it. But general UK editorial usage still keeps "sulphur" in non-technical prose. "Draught" covers beer and horses; "draft" covers documents and military.

Note The adjective forms often keep the -t everywhere: "burnt toast," "a learned scholar" (pronounced "learn-ed"). UK usage is shifting: The Guardian now accepts "learned" as a past tense. Both forms will coexist for decades.

Note These aren't part of the -our/-or rule (they're not French-Latin suffix words). Webster extended his simplification to similar-looking words — some stuck in the US, none crossed back to the Commonwealth.

Note Proper names are fixed regardless: Earl Grey tea, Dorian Gray, 50 Shades of Grey (UK author). The scientist Stephen Gray was English but used the "gray" spelling. There is no rule — just a habit.