Use who when the word is the subject of a verb (the person doing something). Use whom when it’s the object (the person something is done to, or the person after a preposition). Who works like he or she; whom works like him or her.
- Who called you? (He called you.)
- Whom did you call? (You called him.)
The fastest way to decide is the he/him test. And in casual American English, who is accepted almost everywhere; whom still matters in formal writing. This GrammarVista.com USA guide shows you when each one counts.
Key Takeaways
- Who is a subject (like he); whom is an object (like him).
- If him fits, use whom: both end in m.
- Right after a preposition, formal English uses whom.
- Judge whoever and whomever by their role inside their own clause.
- In casual speech and texts, who is perfectly fine.
Subject vs. Object: The Core Rule
Who and whom follow the same subject/object pattern as pronouns you already use without thinking.
The Purdue OWL’s pronoun case chart lists who as subjective and whom as objective, right alongside he and him.
| Role | Use | Same as | Example |
|---|---|---|---|
| Subject (does the action) | who | he, she, they | Who wrote this report? |
| Object of a verb | whom | him, her, them | Whom did the board hire? |
| Object of a preposition | whom | him, her, them | To whom should I send it? |
You’d never say “Him wrote the report,” and the same instinct solves who vs. whom. Pronoun case is one of the core topics on our grammar rules page.
The He/Him Test
Here’s how to run it:
- Turn the part of the sentence with who or whom into a statement.
- Replace who/whom with he or him.
- If he sounds right, use who. If him sounds right, use whom.
Quick rule: Him and whom both end in m. If him fits, whom fits.
Let’s try it:
- (Who/Whom) is coming to dinner? → He is coming. → Who is coming to dinner?
- (Who/Whom) should we invite? → We should invite him. → Whom should we invite?
- The woman (who/whom) I met yesterday is a pilot. → I met her. → The woman whom I met yesterday is a pilot.
With questions, you’ll often need to rearrange the words first. “Whom did you see?” becomes “You saw him.” Towson University’s writing guide recommends the same he/him substitution.
Who and Whom After Prepositions
When the word comes right after a preposition (to, for, with, from, by, about, of), it’s an object, so formal English uses whom: “To whom it may concern,” “With whom did you travel?”
In casual speech, Americans usually move the preposition to the end and use who: “Who did you travel with?” What sounds odd is mixing styles: “With who did you travel?”
| Avoid | Use (formal) | Use (casual) |
|---|---|---|
| To who should I address this? | To whom should I address this? | Who should I address this to? |
| With who are you meeting? | With whom are you meeting? | Who are you meeting with? |
And yes, ending a sentence with a preposition is allowed. Our guide to American-English grammar rules explains why that old “rule” doesn’t hold up.
Whoever vs. Whomever
The same logic applies to whoever and whomever, with a twist: what matters is the word’s role inside its own clause, not in the whole sentence.
Take “Give the extra tickets to whoever needs them.” The object of to is the whole clause whoever needs them. Inside that clause, whoever is the subject of needs (he needs them), so whoever is correct.
- Give the tickets to whomever you choose. (You choose him.)
- Whoever finishes first wins a prize. (He finishes first.)
Quick rule: Ignore the words outside the clause. Find the verb that whoever/whomever belongs to, then run the he/him test on that clause alone.
When “Who” Is Perfectly Fine
In everyday American English, whom has been fading from casual use for a long time. Merriam-Webster notes that who is commonly used as an object in speech and informal writing. “Who did you see at the party?” is standard conversation.
You can comfortably use who in conversation, casual email, text messages, social media, and dialogue in fiction.
Matching your tone to the setting matters as much as the rule. For more on casual registers, see our guide to text slang meanings.
When “Whom” Still Matters
In formal writing, editors and style guides such as The Chicago Manual of Style and the AP Stylebook still distinguish who from whom. Use the traditional rule in academic papers, legal and business documents, cover letters, grant proposals, and published articles.
A good shortcut: if you’d avoid contractions in a document, use whom where it belongs. If it still sounds awkward, rewrite: “Which person did you contact?”
Common Traps
“Whom I think is” (wrong)
Phrases like I think, we believe, or they said get dropped into a clause and make the pronoun look like an object. It isn’t.
Remove the inserted phrase and test: “The candidate who (I think) is best qualified” → He is best qualified. So it’s who.
| Avoid | Use | Test |
|---|---|---|
| Whom shall I say is calling? | Who shall I say is calling? | He is calling. |
| The person whom we believe stole it | The person who we believe stole it | He stole it. |
| Whomever wins will get a bonus. | Whoever wins will get a bonus. | He wins. |
| Who did they promote? (formal writing) | Whom did they promote? | They promoted him. |
Overcorrecting with “whom”
Using whom where who belongs sounds more wrong to many readers than the reverse. At GrammarVista.com USA, our advice is simple: in a formal sentence, run the test rather than guessing whom to sound polished.
Practice: Who or Whom?
Choose who, whom, whoever, or whomever for formal writing.
- ______ left the lights on in the conference room?
- To ______ did you give the keys?
- Please send the file to ______ is managing the account.
- The speaker ______ I think will impress you most goes on last.
Answer key
- Who (He left the lights on.)
- whom (after the preposition to)
- whoever (He is managing the account.)
- who (Drop “I think”: He will impress you most.)
Want more pairs like this? Try lay vs. lie or affect vs. effect, and keep our list of commonly confused words bookmarked. The full set lives in the tricky words section.
The Bottom Line
Who is for subjects, and whom is for objects. Run the he/him test, use whom right after a preposition, and judge whoever/whomever by its own clause.
In casual American English, who is fine almost everywhere. In formal writing, the distinction still counts. For more quick rules like this one, visit the GrammarVista.com USA grammar guide.
Frequently Asked Questions
Is “whom” still used in American English?
Yes, mainly in formal writing. Academic papers, legal documents, cover letters, and publications that follow a style guide still use whom for objects. In everyday conversation and casual messages, most Americans use who in every position, and listeners rarely notice. Choose based on how formal the setting is, then apply the he/him test.
Is it “to who” or “to whom”?
Write “to whom.” A pronoun that comes directly after a preposition such as to, for, or with is an object, so formal English uses whom. If that sounds too stiff, move the preposition to the end and use who instead: “Who should I send this to?” Avoid mixing styles, as in “to who.”
Is it “whoever” or “whomever” after a preposition?
It depends on the clause, not the preposition. In “Give it to whoever asks,” whoever is the subject of asks, so it stays whoever. In “Give it to whomever you choose,” whomever is the object of choose. Isolate the clause, run the he/him test on it, and ignore the preposition outside.
Why is “whom I think is best” wrong?
The inserted phrase “I think” makes the pronoun look like an object, but it is really the subject of “is.” Remove the phrase and test: “he is best,” not “him is best.” So the correct form is “who I think is best.” The same applies with “we believe,” “they said,” and similar phrases.