Question 1

Is it "who to blame" or "whom to blame"?

Accepted Answer

"Whom to blame." The blame is being done to someone — the object slot calls for whom. "You blame him," not "you blame he" — the him-test tells you the object form fits. So the phrase with whom is the grammatically careful one. In casual speech, "who to blame" is widespread and most readers won't notice.

Question 2

What's the difference between "who" and "whom"?

Accepted Answer

Who is the subject — it does the action. Whom is the object — the action happens to it.

Question 3

When do I use "whom"?

Accepted Answer

Use whom when the pronoun is the object of a verb or preposition — when something is done to it.

Question 4

Is it "who should I call" or "whom should I call"?

Accepted Answer

Strictly, "whom should I call" — the caller is doing the calling to someone.