Question 1

What is the difference between Who and Whom?

Accepted Answer

Who does the action; whom receives it. That's the rule in formal English, and it matters most after a preposition ('to whom', 'with whom', 'many of whom'). In everyday speech and most informal writing, who has largely taken over both jobs, and 'Who did you invite?' is normal, natural English rather than a mistake.

Question 2

How do I know if I mean Who rather than Whom?

Accepted Answer

Readers who land here meaning Who rather than Whom are usually searching for phrases like “who or whom”, “to who or to whom”, “when do you use whom”.

Aspect	Who	Whom
Job in the sentence	Subject: does the action	Object: receives the action
Pairs with	he, she, they	him, her, them
Example	'Who called you?'	'To whom should I address this?'
Register	Every style, including formal	Formal; rare in speech

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Which one did you mean?

Who

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