When do I use who, and when can I use whom?

It’s a common question, especially for people who find themselves in a situation where they have to use formal written English, such as a job application, letter of complaint or academic essay. When people find themselves in such situations, especially if they’re unaccustomed to them, replacing who and while with whom and whilst respectively are often seen as convenient shortcuts to formality. And while it is possible to always replace while with whilst, the same is not true of who and whom, and there are specific situations in which we can use whom.

Before figuring it out, I want to look at two incorrect uses of whom, as that’s usually more instructive:

Whom is speaking with me?

The man whom spoke to me on the phone yesterday informed me that I should email you.

In both of these cases, we have to use who. If you really wanted to use whom, we could change the sentences to do so, like this:

Whom am I speaking to?

The man whom I spoke to on the phone yesterday informed me that I should email you.

Now both of these are fine. Can you see the difference in when we use them? Like using I or me, the difference is between whether we’re referring to the subject or object of a verb. We use who to refer to a subject of a verb, the one doing the action, and whom to refer to the object of a verb, the one on the receiving end of an action.

And that’s it! It’s not always easy to immediately identify if we’re referring to the subject or object of a sentence, but it can be done. When trying to decide whether to use who or whom, there are two things to consider: whom does the word refer to (as they’re personal pronouns, they always refer to people), and is this person performing the action in question, or on the receiving end of it? Let’s look at two more quick examples:

Who is speaking?

In this case, it’s fairly straightforward. Speaking is the action, and we want to know who is doing that action, so we’re looking for the subject of the action, and therefore use who. It might also be illustrative to look at a potential answer:

Steve is speaking.

The who in the question therefore refers to Steve, the one doing the speaking, and the answer clearly demonstrates that he is the one doing the speaking.

Whom are you talking to?

Now, I’m talking to my friend, who’s on the phone. I can see that my friend is talking, so I don’t need to ask who’s speaking. Instead, I want to know who’s listening to my friend, i.e. who’s the object of the action of talking. And the answer might be:

I’m talking to Steve.

In this case, my friend is the one doing the action (talking), and Steve is the object, the one being spoken to. Note also that questions with whom often end with a verb and a preposition (which is fine), because we’re looking for the person who is at the receiving end of that verb, and follows it and the preposition in the answer.

Let’s look at a few more examples of the two words used correctly to consolidate:

Who lives here?

Whom do you live with?

The woman who runs the place is over there.

The woman under whom I work is over there.

I don’t know who’s going to the dance.

I don’t know whom I’m going to take to the dance.

It should be a bit clearer now. And if you’re looking at all those examples and thinking you’d usually use who in all the cases where I used whom, it’s important to know that in most contexts, it’s perfectly fine to do so. Outside of very formal language, or a situation where a style guide or individual specifies you should use whom where possible, it’s fine to use who to refer to both subjects and objects. It’s never really necessary to use whom, as the context of the sentence tells you if the person is its subject or object. It’s like the way we use you as both an object and subject pronoun. It never causes confusion. In fact, misusing whom is probably more likely to cause confusion.

In fact, I’d even recommend avoiding whom (and whilst, for that matter), except in cases of formal writing. Very often, it’s a sign of someone trying to impress, and can come across as pretentious, or trying to hide a perceived weakness in one’s language. I’m always suspicious of overly-formal or flowery language in general, and throwing a bunch of whom’s into your speech is often a sign of that. Just use who, and keep it simple, and you’ll be fine. Unless you’re trying to impress a grammar nerd, in which case they’ll probably be impressed by your masterful use of whom.