Use "who" when it's the subject doing the action ("Who called you?" — he called). Use "whom" when it's the object receiving the action ("Whom did you call?" — you called him). Trick: if you can replace the word with "he", use "who"; if you can replace it with "him", use "whom" — both end in M.
"Whom" is fading from everyday speech, but it's still expected in formal and careful writing — and there's a genuinely easy trick to get it right every time.
The rule
- Who is a subject pronoun — it does the action, like "he" or "she". "Who wrote this?" (He wrote this.)
- Whom is an object pronoun — it receives the action, like "him" or "her". "Whom did you ask?" (You asked him.)
The he/him trick
This is the fastest way to check: mentally answer the question using "he" or "him".
- If the answer is "he" → use who. "Who is coming?" → He is coming.
- If the answer is "him" → use whom. "To whom should I send this?" → Send it to him.
Both "whom" and "him" end in M — an easy way to remember the pairing.
More examples
- "Who is responsible for this?" (He is responsible — subject.)
- "Whom do you trust the most?" (You trust him the most — object.)
- "The man who called was polite." (He called — subject.)
- "The man whom I met was polite." (I met him — object.)
Is it OK to just always use "who"?
In casual speech and writing, yes — "whom" is increasingly rare and "who" is broadly accepted even in object position ("Who did you ask?"). But in formal writing, after prepositions, or when precision matters, "whom" is still expected: "To whom it may concern," "for whom the bell tolls."
Frequently Asked Questions
Is "whom" old-fashioned?
It's increasingly rare in casual speech, where "who" is now widely accepted even as an object. Formal writing, especially after a preposition ("to whom", "for whom"), still expects "whom".
What's the fastest way to check who vs whom?
Answer the question with "he" or "him". If "he" fits, use "who". If "him" fits, use "whom" — both end in M.
Is "whom" ever wrong to use?
Yes — using "whom" as a subject ("Whom is calling?") is a common overcorrection. If the answer would be "he", it should be "who", not "whom".