Use who as the subject of a verb (who called you?). Use whom as the object of a verb or preposition (to whom should I address this?).
The Core Difference
“Who” and “whom” work exactly like “he” and “him”. “Who” (like “he”) performs the action of the verb — it is the subject. “Whom” (like “him”) receives the action, or follows a preposition — it is the object.
Because “whom” sounds formal, it is disappearing from everyday spoken English, especially at the start of questions (“Who did you invite?” is now standard even though “whom” is technically correct). It survives mainly after prepositions (to whom, for whom, with whom) and in formal writing.
- subject → who (= he/she/they): Who is calling? (He is calling.)
- object → whom (= him/her/them): To whom should I speak? (Speak to him.)
Who and Whom in Context
Who wrote this report?
Whom did you invite to the meeting?
This is the manager whom I mentioned earlier.
To whom it may concern,
Who is responsible for the decision, and to whom do they report?
Common Mistakes
| Incorrect | Correct | Why |
|---|---|---|
| ✗ whom is calling? | ✓ who is calling? | subject of “is calling” |
| ✗ who did you give it to? | ✓ whom did you give it to? (or informal: who...to) | object of “to” |
| ✗ the person who I spoke to | ✓ the person whom I spoke to (formal) | object of “to” |
| ✗ for who it may concern | ✓ for whom it may concern | object of “for” |
| ✗ whom called earlier? | ✓ who called earlier? | subject of “called” |
The He/Him Test: Rephrase the question as a statement using “he” or “him”. If “he” fits, use who. If “him” fits, use whom.
Both him and whom end in M — an easy way to remember that whom is the object form, just like him.
Related Questions
- Who vs Whom — full confusing-words comparison page with additional examples and exercises.
- All Confusing Words — browse all 300+ word-pair guides.
- All Questions — more quick-answer pages.
- Grammar Quiz — test your knowledge of confusing word pairs.
Frequently Asked Questions
What is the fastest test for who vs whom?
Replace the who/whom with “he” or “him” and see which fits in a restated sentence. “Who called?” becomes “he called” — that works, so use “who”. “___ did you call?” becomes “you called him” — “him” fits, so use “whom”.
Why does whom feel old-fashioned?
In casual modern English, especially spoken, “whom” has largely been replaced by “who” in most positions, including as the object of a verb at the start of a sentence (“Who did you see?” instead of “Whom did you see?”). “Whom” survives mainly in formal writing and directly after prepositions.
Is to whom it may concern still correct?
Yes, and it remains the standard formal opening for a letter addressed to an unknown recipient, because “whom” is the object of the preposition “to”. This fixed phrase has not been replaced by “to who” in formal correspondence.
Do I need whom after every preposition?
In formal or written English, yes — prepositions (to, for, with, from, by) are always followed by the object form “whom”: with whom, for whom, from whom. In informal speech, many speakers move the preposition to the end and use “who” instead (“Who did you go with?”).
Is it acceptable to always use who instead of whom?
In informal speech and writing, yes — using “who” everywhere is now widely accepted and does not sound wrong to most native speakers. In formal writing, exams, and professional correspondence, however, the who/whom distinction is still expected and checked.
How do I decide in a relative clause like the person who/whom I met?
Isolate the clause and apply the test: “I met ___” becomes “I met him”, so “him” fits and the formal choice is “whom”: “the person whom I met”. In everyday speech, “the person who I met” or simply “the person I met” are both extremely common.
Is whomever ever correct?
Yes — “whomever” is the object form of “whoever”, used the same way as “whom”: “Give the prize to whomever arrives first” (object of “to”). Like “whom”, it is increasingly rare outside formal writing.
Do IELTS and Cambridge exams expect correct who/whom use?
Formal writing tasks (especially letters and reports) reward correct use of “whom” after prepositions and in formal openings like “To whom it may concern”. In speaking sections, examiners do not expect “whom”, since natural spoken English overwhelmingly favours “who”.
What is a simple memory trick for whom?
Remember that both “whom” and “him” end in the letter M — whenever “him” would fit in the rephrased sentence, choose the M-word, “whom”.
Does British English use whom differently from American English?
Both varieties follow the same grammatical rule, but British formal and legal writing tends to preserve “whom” slightly more often in professional correspondence, while American everyday usage has moved further toward “who” in nearly all contexts.