Grammar 101: How to use who and whom correctly?

What’s the difference between who and whom? These are two words that cause a lot of confusion, even for native-English speakers. So, it’s well worth taking a few minutes to know the difference between the two. Below, we’ve provided an easy guide on understanding the grammatical rules. We’ve also given some examples on how to use who and whom correctly. If you want to avoid mistakes in using who vs whom, read on.

There are a few rules when you should use who and whom. “Who” is a subjective pronoun. “Whom” is an objective pronoun. That simply means that “who” is always subject to a verb, and that “whom” is always working as an object in a sentence. We’ve explained what subjects and objects in a sentence are. 

But what does that mean? “Who,” the subjective pronoun, is the doer of an action. For example, “That’s the girl who scored the goal.” It is the subject of “scored” because the girl was doing the scoring. Then, “whom,” as the objective pronoun, receives the action. For instance, “Whom do you like best?” It is the object of “like”. 

General rule for who vs whom: 

• Who should be used to refer to the subject of a sentence. 

• Whom should be used to refer to the object of a verb or preposition. 

Just be careful, because there is an exception: There is one context in which you should always use whom: after a preposition at the beginning of a sentence or clause. For example, To whom did you address that letter? (Not “to who”). And, My teacher, for whom I’m doing some research, is currently in a meeting. (Not “for who”).

The difference between “who” and “whom” is the same as the difference between “I” and “me;” “he” and “him;” “she” and “her;” etc. "Who", like other pronouns such as: I he, and she, is a subject. So, it is the person performing the action of the verb. On the other hand, "whom", acts like me, him, and her in a sentence. It is the object. Therefore, it is the person to/about/for whom the action is being done. 

Whom is also the correct choice after a preposition: with whom, one of whom, not “with who, one of who.” 

We explained that “who” is a pronoun like “I” or “he.” Also, “whom” is a pronoun like “me” and “him.” So, sometimes it can help you to rewrite the sentence and replace who/whom with another pronoun so that you can see the relationships more clearly. 

If you can replace the word with “he” or “’she” then you should use who. However, if you can replace it with “him” or “her,” use whom. Let’s look at some examples.

Just remember that if you can replace a word with “he” or “she” then you should use "who". However, if you can replace it with “him” or “her,” use "whom". We’ll test this in the following sentences. 

Example sentences: Correct use of who 

• This is who warned me. (It is He/she warned me. Not “him/her” warned me) 

• Jack is the one who wants to go. (He/she wants to go. Not “him/her” wants to go) 

• I need to know who makes the final decision. (He/she makes the final decision. Not “him/her” makes the final decision). 

• I know who your best friend is! (He/she is your best friend. Not him/her is your best friend).   

Example sentences: Correct use of whom 

• With whom am I speaking? (I am speaking with him/her. Not I am speaking with he/she) 

• To whom this may concern. (This concerns him/her. Not this concerns he/she) 

• A number of friends went to the cinema, one of whom was the birthday boy. (The birthday boy was one of them. Not the birthday boy was one of they.) 

• Actually, she knew very little about the man with whom she had promised to spend the summer. (She has promised to spend the summer with him. Not she has promised to spend the summer with he.)

Now that we’ve gone through the grammar rules and shown you some examples, let’s test your understanding with this quick “Who vs Whom” test. 

Click here to view the answer key.

We’ve covered the basics of who vs whom, but it can get slightly more complicated. For example, you use the tip we’ve presented earlier that if you can replace a word with “he” or “she” then you should use who. And, if you can replace it with “him” or “her,” use whom. But what if that doesn’t work, or it doesn’t fit your sentence? 

We’ve used the following example sentence before: 

A number of friends went to the cinema, one of who/whom was the birthday boy. 

Complex sentences: Clauses

This sentence is difficult because it contains a clause. A complex sentence contains an independent clause and one or more dependent clauses. An independent clause can stand alone as a sentence, but a dependent clause (even though it has a subject and a verb) cannot stand alone. In the example, “A number of friends went to the cinema” is one clause. The other clause is “one of who/whom was the birthday boy.” 

The last clause is adjectival clause. To put it simply: it means this part of the sentence aims to tell us more about the other part of the sentence. Who went to the cinema? Friends and one of them was the birthday boy. 

The key lies in the subject and object of the clauses. In “whom was the birthday boy,” “the birthday boy” is the subject, “was” is the verb, and “whom” is the object.  

Need to read more on subjects and objects in sentences? Check out our other blog post: Grammar 101: Subjects and Objects in English. 

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