Who vs Whom

1. Subject vs Object: The Core Distinction

Who functions as the subject of a verb — the person or thing doing the action. "Who broke the window?" (Who is the subject performing the breaking.) "The woman who lives next door is a doctor." (Who is the subject of "lives.") Think of "who" as equivalent to "he," "she," or "they" — all subject pronouns.

Whom functions as the object of a verb or preposition — the person or thing receiving the action. "Whom did you invite?" (Whom is the object receiving the inviting.) "The person to whom I spoke was helpful." (Whom is the object of the preposition "to.") Think of "whom" as equivalent to "him," "her," or "them" — all object pronouns.

2. The He/Him Substitution Test

The most reliable way to choose between "who" and "whom" is the he/him substitution test. Rearrange the sentence to create a statement, then substitute "he" or "him." If "he" fits, use "who." If "him" fits, use "whom." The "m" in "him" and "whom" helps you remember they go together.

Example 1: "(Who/Whom) wrote this book?" → Rearrange: "He wrote this book" or "Him wrote this book"? → "He" works, so use "Who" wrote this book.

Example 2: "(Who/Whom) should I trust?" → Rearrange: "I should trust he" or "I should trust him"? → "Him" works, so use "Whom" should I trust.

Example 3: "The candidate (who/whom) they elected." → Rearrange: "They elected he" or "They elected him"? → "Him" works, so use "whom" they elected.

3. After Prepositions: Always Whom

When a pronoun follows a preposition (to, for, with, by, from, about, etc.), you must use the object form. Since "whom" is the object form, it always follows prepositions in formal English: "To whom it may concern," "With whom are you traveling?" "For whom the bell tolls," "From whom did you hear this?"

This is one area where "whom" remains standard even in casual speech, particularly in set phrases like "to whom it may concern" or "for whom." However, in very informal contexts, people often restructure sentences to avoid preposition + whom: instead of "With whom are you going?" they say "Who are you going with?" (ending with the preposition).

4. Declining Use of Whom in Modern English

Whom is disappearing from casual speech. In everyday conversation, most native English speakers use "who" for both subject and object positions: "Who did you see?" instead of "Whom did you see?" This has been happening for decades, and "who" as a universal interrogative is now standard in informal contexts.

However, whom persists in formal writing, professional communication, legal documents, academic papers, and standardized tests. Style guides and grammar authorities still require "whom" in object positions, especially after prepositions. Using "whom" correctly signals education and attention to formal grammar conventions.

The key is to match your usage to your context. In an email to a friend: "Who did you talk to?" is perfectly fine. In a formal report: "The stakeholders with whom we consulted provided valuable feedback" maintains professional standards. Know your audience and adjust accordingly.

5. Relative Clauses: Who vs Whom in Dependent Clauses

In relative clauses (clauses that provide additional information about a noun), choose "who" or "whom" based on the pronoun's role within that clause, not its role in the main sentence. Look at what happens inside the relative clause itself.

Who in relative clauses: "The student who scored highest won the scholarship." → Within the relative clause, "who" is the subject of "scored." (He scored highest.)

Whom in relative clauses: "The student whom the professor recommended got the job." → Within the relative clause, "whom" is the object of "recommended." (The professor recommended him.)

Here's a complex example: "The lawyer whom I thought was handling the case retired." This one tricks many people. The relative clause is "whom I thought was handling the case." Within this clause, the pronoun is actually the subject of "was handling" (he was handling the case), so it should be "who", not "whom": "The lawyer who I thought was handling the case retired."

6. Common Set Phrases and Idioms

Certain phrases have standardized forms that use "whom" and are unlikely to change even as casual usage evolves. These include: "To whom it may concern" (formal letter opening), "For whom the bell tolls" (literary reference), "Whom the gods would destroy" (classical allusion), and "To whom much is given, much is required" (proverb).

Additionally, "whoever" and "whomever" follow the same subject/object rules. "Give it to whoever wants it" uses "whoever" because it's the subject of "wants" within its clause (even though the whole clause is the object of "to"). But "Give it to whomever you choose" uses "whomever" because it's the object of "choose" (you choose him/her).

❌ Incorrect: "Whom is coming to the party?"

Why it's wrong: The pronoun is the subject of "is coming" (she is coming), so you need the subject form "who."

✅ Correct: "Who is coming to the party?"

❌ Incorrect: "Who did you give the keys to?"

Why it's wrong: While grammatically the object of "to" should be "whom," this informal construction ending with a preposition is widely accepted. However, in formal writing, restructure it.

✅ Correct (formal): "To whom did you give the keys?"

✅ Acceptable (informal): "Who did you give the keys to?"

❌ Incorrect: "The person who I spoke to was helpful."

Why it's wrong: In formal writing, the pronoun is the object of the preposition "to" (I spoke to him), so it should be "whom."

✅ Correct (formal): "The person to whom I spoke was helpful."

✅ Acceptable (informal): "The person who I spoke to was helpful."

❌ Incorrect: "Whom do you think will win?"

Why it's wrong: Many people mistakenly use "whom" because "you think" makes it seem like an object. But the pronoun is actually the subject of "will win" (he will win), so use "who."

✅ Correct: "Who do you think will win?"

❌ Incorrect: "The candidate who we voted for won."

Why it's wrong: In formal writing, the pronoun is the object of "for" (we voted for her), so it should be "whom." However, this is increasingly accepted in casual writing.

✅ Correct (formal): "The candidate for whom we voted won."

✅ Acceptable (informal): "The candidate who we voted for won."

❌ Incorrect: "Give it to whomever wants it."

Why it's wrong: Although the entire clause is the object of "to," within that clause the pronoun is the subject of "wants" (he wants it), so use "whoever."

✅ Correct: "Give it to whoever wants it."