about who (whom) to

Use who for subjects (he/she/they) and whom for objects (him/her/them). Quick test: swap he/him - if him fits, use whom.

Below are concise rules, fast checks, many wrong/right pairs grouped by context, and ready-to-paste rewrites so you can fix sentences immediately.

Quick answer

Who = subject (replace with he/they). Whom = object (replace with him/them). If a preposition comes before the pronoun (to/for/with/about) or the pronoun receives the action, use whom.

Who → he / Whom → him (use this swap every time)
If the word follows a preposition, prefer whom in formal writing
In casual speech, who often replaces whom; use whom for formal tone

Core explanation: the substitution test

Find the clause containing who/whom and mentally replace the pronoun with he or him (or they/them). If he/they fits, write who. If him/them fits, write whom.

This applies inside relative clauses and questions: the clause's internal subject vs. object role decides the choice.

Subject? Use who (e.g., "Who called?" → "He called").
Object or follows a preposition? Use whom (e.g., "You saw whom?" → "You saw him").

Wrong: Who are they inviting?
Right: Whom are they inviting? (They are inviting him)
Wrong: Who wants to join the team?
Right: Who wants to join the team? (He wants to join)

Common patterns that cause errors

Questions with trailing prepositions, relative clauses, and coordinated nouns are frequent trouble spots. Test inside the clause: "the person who/whom ___" - decide whether that blank is the clause subject or object.

Trailing prepositions: "Who did you give it to?" → formal: "To whom did you give it?"
Relative clauses: "the woman whom we hired" (object) vs "the woman who hired us" (subject)
Coordinated nouns: test the case for the whole phrase ("between you and me," not "between you and I")

Work - Wrong: Who did you give the document to?
Work - Right: To whom did you give the document? (You gave it to him)
Work - Wrong: The engineer who the client praised will lead the project.
Work - Right: The engineer whom the client praised will lead the project.

Memory tricks and quick checks

Short checklist: (1) Is the pronoun doing the action in its clause? → who. (2) Is it receiving the action or following a preposition? → whom. (3) Swap he/him to confirm.

If a correction makes the sentence stiff, prefer a natural rewrite rather than forcing whom into casual copy.

Swap test: insert he/him - whichever sounds right gives who/whom
If a preposition precedes it (to/for/with/about), lean toward whom in formal writing
When in doubt for formal documents, use whom

Register and real usage: when whom is optional

Native speakers often use who in object positions in speech and informal writing; readers still understand. Whom appears more in formal emails, legal text, and academic writing.

Decide by audience: choose whom for grant proposals and formal letters; who is fine in chats and quick emails. If you want precision without sounding archaic, rewrite the sentence to avoid awkward phrasing.

Formal = prefer whom after prepositions and in object positions
Informal = who is widely accepted
Rewrite to avoid sounding stilted instead of forcing whom into casual copy

Work:
Casual: "Who should the board contact about the audit?"
Formal: "Whom should the board contact about the audit?"
Casual: "Who are you going with tonight?" is natural in group texts; "With whom are you going tonight?" suits invitations or printed materials.

Rewrite help: three fast fixes and copyable rewrites

Three-step fix: (1) Run the he/him test. (2) Replace who with whom if the test chooses him. (3) If the result reads stiff, move the preposition before the pronoun or rephrase to avoid the pronoun.

Move preposition: "Who did you talk to?" → "To whom did you talk?"
Drop the pronoun: "The person (whom) I invited" → "The person I invited."
Use active voice: "The student whom the teacher praised" → "The teacher praised the student."

Rewrite:
Wrong: "Who did you give the book to?" →
Formal: "To whom did you give the book?" → Natural: "Who did you give the book to?" (acceptable in casual contexts)
Rewrite:
Wrong: "The committee, who we selected, will meet." → Copyable: "The committee we selected will meet." or "The committee, whom we selected, will meet."
Rewrite:
Wrong: "Who should I speak with about the invoice?" →
Formal: "With whom should I speak about the invoice?" → Alternate: "Who should I contact about the invoice?"

Try your own sentence

Test the whole sentence, not only the fragment - context makes the right answer clearer.

Examples you can copy: work, school, and casual pairs

Each pair shows a typical mistake and a formal correction. In casual use the 'wrong' version may pass; for formal texts use the 'right' version.

Work - Wrong: Who did you send the budget to?
Work - Right: To whom did you send the budget?
Work - Wrong: Who should I report this to?
Work - Right: To whom should I report this?
Work - Wrong: Who did the manager promote?
Work - Right: Whom did the manager promote? (The manager promoted him)
School - Wrong: The student who the professor praised sat at the front.
School - Right: The student whom the professor praised sat at the front.
School - Wrong: Who did the teacher give the assignment to?
School - Right: To whom did the teacher give the assignment?
School - Wrong: That's the researcher who we cited in the paper.
School - Right: That's the researcher whom we cited in the paper.
Casual - Wrong: Who are you going with tonight?
Casual - Right: With whom are you going tonight? (formal) - "Who are you going with?" is fine in chat.
Casual - Wrong: That's the guy who I met at the concert.
Casual - Right: That's the guy whom I met at the concert.
Casual - Wrong: Who did you leave the keys with?
Casual - Right: With whom did you leave the keys? (Or "Who did you leave the keys with?" in speech)

Hyphenation notes (when related words appear)

Hyphenation doesn't affect who vs whom. Whoever/whomever follow the same subject/object logic inside their clause.

Whoever = subject within its clause; whomever = object within its clause (test with he/him inside the clause)
Don't hyphenate who/whom (no "who-ever")
Example: "Give the prize to whomever you choose." (You choose him → whomever)

Usage: Whoever wins the race will get a bonus. (subject)
Usage: Give the prize to whomever you select. (object)

Spacing and punctuation tips that affect clarity

Commas around a clause don't change whether who/whom is subject or object - run the substitution test inside the clause. Moving the preposition before the pronoun cleans up formality and spacing.

If you can omit the relative pronoun without losing meaning, omission often produces a cleaner sentence.

Test inside comma-delimited clauses for subject/object role
Move the preposition before the pronoun for formal tone: "To whom" vs "who ... to"
Delete the pronoun when possible: "The person I called" instead of "The person whom I called"

Wrong: The author who the committee invited, accepted the award.
Right: The author whom the committee invited accepted the award.
Cleaner: "The author the committee invited accepted the award." (drop the pronoun)

Grammar notes: related pronoun issues to watch for

When you check who/whom, also scan for I/me errors, misuse of who/that/which, and omitted relative pronouns. Fixing these together improves clarity quickly.

If multiple fixes are needed, consider rewriting the sentence rather than patching each problem.

I vs. me: "Mark and I reviewed" (subject) vs "between Mark and me" (object)
Who vs that/which: use who for people; that/which for things
Omitting the relative pronoun often produces the clearest sentence ("The person I invited...")

Wrong: The rules, which I and Mark reviewed, are final.
Right: The rules, which Mark and I reviewed, are final.
Wrong: Someone who everyone admires called.
Right: Someone whom everyone admires called. (object after admire → whom)

FAQ

Is whom dying - can I just use who everywhere?

In speech and informal writing many use who for objects and it's generally understood. For formal documents or anything requiring precision, use whom where the pronoun is an object or follows a preposition.

How do I decide between "to who" and "to whom"?

Do the he/him swap: if you would say "to him", use "to whom". In formal writing, prefer putting the preposition before the pronoun ("To whom...").

Can you start a sentence with Whom?

Yes. "Whom did you invite?" is correct and clear in formal contexts. It may sound stilted in casual speech, where "Who did you invite?" is fine.

Should I always move the preposition before whom?

Moving the preposition before the pronoun ("With whom...") is more formal and often clearer. In informal writing, ending the sentence with the preposition is acceptable.

What's the fastest way to fix many who/whom errors in a draft?

Make one pass: for each who/whom, apply the he/him test. If many corrections make sentences awkward, rewrite the clause or drop the pronoun where possible.

Need help editing a sentence now?

When in doubt, run the substitution test, then paste one of the rewrites above. For quick checks, a grammar tool that shows the he/him swap and suggests rewrites can save time and teach the pattern.