Who vs. Whom— A Complete Guide to Using Them Correctly

Many people, including native English speakers, struggle with knowing when to use who and whom. These two words are often confused because they serve similar functions but have different grammatical roles.

The good news? There’s a simple trick to determine which one to use, and this guide will explain everything you need to know—from basic rules to advanced grammar tips, complete with examples and a quiz to test your understanding.

By the end of this article, you’ll be using who and whom like a pro!

Who vs. Whom: The Key Grammar Rules

Understanding the difference between who and whom starts with knowing about subjects and objects in a sentence.

• Who is a subject pronoun (like he, she, or they). It refers to the person doing the action.
• Whom is an object pronoun (like him, her, or them). It refers to the person receiving the action.

A Simple Trick to Remember

If you’re unsure whether to use who or whom, replace it with he/she or him/her in the sentence:

✔ If he/she fits, use who.
✔ If him/her fits, use whom.

Example 1: Who vs. Whom in a Question

• Who/Whom did you call?
  • Test: Did you call he? ✖ (Incorrect)
  • Test: Did you call him? ✔ (Correct)
  • Answer: Whom did you call?
• Who/Whom is knocking at the door?
  • Test: He is knocking at the door. ✔ (Correct)
  • Test: Him is knocking at the door. ✖ (Incorrect)
  • Answer: Who is knocking at the door?

When to Use “Who”

Since who is a subject pronoun, use it when referring to the doer of an action.

Examples of “Who” in Sentences

1. Who won the championship? (He/She won the championship.)
2. This is the scientist who discovered the new element. (He/She discovered the element.)
3. Who made the final decision? (He/She made the final decision.)
4. Can you tell me who is responsible for this project? (He/She is responsible.)
5. I don’t know who left the door open. (He/She left the door open.)

When to Use “Whom”

Since whom is an object pronoun, use it when referring to the person receiving the action of a verb or preposition.

Examples of “Whom” in Sentences

1. To whom should I address this letter? (I should address this letter to him/her.)
2. The manager, one of whom is retiring, hosted the meeting. (One of them is retiring.)
3. She was unsure about whom to invite to the wedding. (She was unsure about inviting him/her.)
4. With whom are you traveling? (I am traveling with him/her.)
5. The professor, for whom I conducted research, wrote me a recommendation. (I conducted research for him/her.)

Advanced Rule: Who vs. Whom with Prepositions

There is one case where “whom” is always correct—when it comes after a preposition (e.g., to, for, with, by, from).

Examples:

• To whom was the letter written? (Not “To who”)
• She met a professor, with whom she discussed her research.
• This is the person for whom I made the presentation.
• He is a politician about whom many books have been written.

Common Mistake: Preposition Placement

Many English speakers place the preposition at the end of a sentence instead of at the beginning. This is common in informal speech.

❌ Who should I send this email to? (Incorrect in formal writing)
✔ To whom should I send this email? (Correct in formal writing)

In everyday conversation, it’s okay to say: Who should I send this email to? But in formal writing, keep the preposition at the beginning and use whom.

Complex Sentences: Who vs. Whom in Clauses

Sometimes, who and whom appear in relative clauses (extra information about a noun). This can make choosing the correct word trickier.

• This is the artist who won the award. (Who is correct because he won the award.)
• She hired a tutor whom her friend recommended. (Whom is correct because her friend recommended him.)

Breaking It Down

• Who is used when the clause describes the subject.
• Whom is used when the clause describes the object.

Who vs. Whom: Quick Quiz

Test your knowledge! Choose the correct word in each sentence:

1. ___ is responsible for the final decision? (Who/Whom)
2. She met a mentor ___ she admired. (Who/Whom)
3. To ___ should we send this package? (Who/Whom)
4. The students, one of ___ received a scholarship, were excited. (Who/Whom)
5. ___ will be speaking at the conference? (Who/Whom)
6. The teacher, for ___ I wrote a report, praised my work. (Who/Whom)
7. ___ do you think will win the election? (Who/Whom)
8. He met a journalist with ___ he had an interesting conversation. (Who/Whom)
9. ___ left the meeting early? (Who/Whom)
10. She didn’t know ___ to invite to the event. (Who/Whom)

Answer Key

1. Who
2. Whom
3. Whom
4. Whom
5. Who
6. Whom
7. Who
8. Whom
9. Who
10. Whom

Final Thoughts: Mastering Who vs. Whom

Understanding when to use who and whom is easier than it seems:

• Use “who” when referring to the subject (he/she).
• Use “whom” when referring to the object (him/her).
• Always use “whom” after a preposition.

By practicing with examples and following the he/him trick, you’ll avoid mistakes and use who and whom with confidence!

For more grammar lessons, check out Subjects and Objects in English.