Who vs. Whom
“Who” is used for subjects and is also common for objects in ordinary modern English; “whom” is the traditional object form and remains most common in formal writing, especially after a preposition.
Use “who” when the pronoun is the subject. “Whom” is the object form, especially in formal writing and after a preposition. In everyday English, “who” is very often used where formal grammar would permit “whom.”
Key details
Choose the right form
| Sentence role | Usually choose | Practical cue |
|---|---|---|
| subject of its clause | who | Compare with he/she/they. |
| object in formal style | whom | Compare with him/her/them. |
| after a fronted preposition in formal prose | whom | For example: “to whom”. |
| ordinary conversational object position | who is common | Modern usage often replaces whom with who. |
In modern speech, “whom” is relatively formal and “who” often appears where very formal grammar would prescribe “whom”; register matters.
Quick tests
he/him substitution
Inside the relevant clause, would “he/she/they” fit or would “him/her/them” fit?
If yes: Subject-form result points to “who”; object-form result can point to “whom” in formal style.
If no: Recheck the clause boundary; do not test against an unrelated verb.
Caveat: Use this as a diagnostic cue, not as a universal replacement rule; sentence meaning and grammatical structure still control the final choice.
Usage notes
Further guidance
He Him Test
A useful diagnostic is to substitute he/him or she/her for the relevant clause. If “he” fits, who is likely right; if “him” fits, whom may be right in formal style. Test the pronoun inside its own clause, not against a word elsewhere in the sentence.
Modern Usage
Cambridge notes that “whom” is much more common in writing than in speech and is not used very often in ordinary conversation. Merriam-Webster likewise warns against hypercorrect “whom” where the pronoun is actually the subject of its clause.
Prepositions
“Whom” is especially stable immediately after a preposition in formal prose: “the person to whom I wrote.” More conversational English often moves the preposition to the end and uses “who”: “the person who I wrote to.”
Subject Vs Object
Use “who” for the person performing the action: “Who called?” Use “whom” as an object in formal style: “Whom did you call?” or, more formally, “To whom did you speak?”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Who, whom — Cambridge Grammar (opens in a new tab)Cambridge University Press · Who/whom roles and formality
- Hypercorrections: a “whom” too far (opens in a new tab)Merriam-Webster · Modern usage and hypercorrection note