When should I use “who” or “whom” in a sentence?
Quick answer
Use “who” when the pronoun is the subject of its clause—the person doing the action. Use “whom” when it is the object of a verb or preposition. Check the clause containing the pronoun, even inside a longer sentence. In everyday conversation, “who” often appears where formal writing would use “whom,” particularly when a preposition comes at the end. [S1]
The question, the details, the next step.
I keep getting stuck on “who” versus “whom.” Is there a quick way to decide?
Ask what job the pronoun is doing in its own clause. If it is the subject—the person doing the action—use “who.” If it is the object of a verb or a preposition, formal grammar uses “whom.” Purdue OWL makes this subject-versus-object distinction and notes that conversational English often uses “who” in object positions too. [S1]
A quick substitution can help: try “he” or “she” for “who,” and “him” or “her” for “whom.” For example, “Who called?” becomes “She called,” so “who” fits. In “Whom did you call?” the answer is “I called him,” so formal writing uses “whom.” Treat this as a check on the pronoun’s role, not just its place near the beginning or end of a sentence.
What about a question like “Who did you invite?” It sounds natural, but I thought “whom” was right.
You’re noticing two things at once: the pronoun’s grammatical role and the style people use in conversation. In “Who did you invite?” the pronoun is the object of “invite,” so “whom” is the formal choice: “Whom did you invite?” In everyday English, “Who did you invite?” is common and sounds natural. [S1]
For a formal document, you could write “Whom did you invite?” or recast the sentence: “Which guests did you invite?” For casual dialogue or a conversational message, “Who did you invite?” is usually the more natural-sounding option. The substitution test explains the formal choice—“I invited them”—but it does not mean every conversational sentence needs to sound formal.
How do I handle embedded clauses, like “I spoke to the person who/whom you recommended”?
Check the clause that contains the pronoun, not the role of the whole phrase in the larger sentence. In “I spoke to the person whom you recommended,” the embedded clause is “you recommended ___.” “You” is the subject, and the person recommended is the object. So “whom” is the formal choice; “who” is common in conversational English. [S1]
Compare it with “I spoke to the person who recommended you.” The embedded clause is now “___ recommended you.” The pronoun is the subject doing the recommending, so “who” is the choice in both formal and conversational writing.
The test is local: fill the blank in the clause. “You recommended him” points to formal “whom”; “He recommended you” points to “who.”
And what if the pronoun follows a preposition, or the preposition is at the end? Could you give me a quick method I can reuse?
When a preposition comes directly before the pronoun, formal writing uses “whom”: “To whom should I send this?” In a relaxed sentence that leaves the preposition at the end, “Who should I send this to?” is conversational and natural; Purdue OWL notes this common preference for “who” in conversation. [S1]
Use this short editing routine:
- Find the clause containing “who” or “whom,” including an embedded clause.
- Identify the verb or preposition connected to the pronoun.
- Try a subject form (“he/she”) or an object form (“him/her”) to check its role.
- If it is an object, choose “whom” for a formal tone; consider “who” for ordinary conversation.
- Read the full sentence aloud and choose the version that suits the audience.
Worked example: “The editor ___ I asked replied.” The clause is “I asked ___”; “I asked him” shows an object. Use “whom” in formal prose (“The editor whom I asked replied”) or “who” in conversational prose (“The editor who I asked replied”). The source explains the grammatical distinction and notes conversational usage; it does not prescribe one style for every audience or sentence. [S1]
A practical checklist
Locate the clause containing the pronoun, even if it is embedded.
Check whether the pronoun is doing the action or receiving it.
Use “he/she” versus “him/her” as a quick role check.
Use “whom” for an object in formal writing; consider conversational “who.”
Read the sentence aloud to check that the choice fits the tone.
A few more useful answers
Is “who did you speak to?” acceptable in conversation?
It is a common conversational form. In more formal writing, you can use “to whom did you speak?” [S1]
Should I always use “whom” after a preposition?
Use “whom” when the pronoun is the object of a preposition in formal writing, as in “with whom.” Everyday phrasing often puts the preposition at the end and uses “who,” as in “who I went with.” [S1]
What should I do if the substitution test feels awkward?
Rewrite the sentence temporarily with “he/she” or “him/her,” then restore the name or pronoun. If the sentence is still hard to follow, rewording it may be clearer than debating the choice.
Sources
References used for this guide.
- [S1] Pronoun Case — Purdue OWL owl.purdue.edu · Checked