Who vs Whom: What’s the Difference? (+ Easy Rule)

Many English learners struggle with who vs whom. Is “whom” only for formal English? Is it disappearing? In this clear grammar guide, you will learn the simple rule for who vs whom and how to use both correctly.

“Who” and “whom” are interrogative and relative pronouns — and they cause confusion even for native speakers.

Many people avoid using whom altogether. Some believe it’s only for formal writing. Others use it randomly because it sounds sophisticated.

But if you want to use English accurately — especially in formal writing or exams like B2 First or C1 Advanced — you should understand the difference properly.

The good news? The rule is actually simple.

When Do We Use Who?

We use who in the subject position of a sentence.

That means who performs the action.

Structure:

Who + verb

Examples:

• Who bought you that ring?
• Who called you last night?
• The woman who lives next door is a doctor.
• I know someone who speaks five languages.

In each sentence, who is doing the action.

A quick test:

If you can replace it with he, she, or they, use who.

Example:

• Who took my pen?
  → He took my pen. ✔ (subject)

When Do We Use Whom?

We use whom in the object position.

That means whom receives the action.

Structure:

Subject + verb + whom

Examples:

• The man whom you invited to dinner.
• The actor whom we saw on TV last night is sitting over there.
• Simon was happy because all the friends whom he invited came to the party.
• Jack met a girl whom he believed worked at the café.

In these examples, someone else performs the action — and whom receives it.

Quick test:

If you can replace it with him, her, or them, use whom.

Example:

• Whom is the book about?
  → The book is about him. ✔ (object)

Whom after Prepositions

Whom is also used after prepositions — especially in formal English.

Examples:

• To whom are you speaking?
• For whom the bell tolls.
• She was someone with whom he wanted to spend the rest of his life.
• This is the client to whom we owe money.

Notice that in everyday English, native speakers often move the preposition to the end and use who instead:

• Who are you speaking to?
• The person who he wanted to spend his life with.

Both are correct — but the “preposition + whom” structure sounds more formal.

Common Mistakes

❌ To who do you want to talk?

✔ To whom do you want to talk?

✔ Who do you want to talk to? (more natural in speech)

❌ This is the man to whom we own money.

✔ This is the man to whom we owe money.

The Simple Trick to Remember

Ask yourself:

• Can I replace it with he/she? → Use who.
• Can I replace it with him/her? → Use whom.

That’s it.

Grammar doesn’t have to be dramatic.

More Correct Examples

• This is the man who sold us the house.
• Sheila was someone with whom he wanted to build a future.
• Laura is a girl who always drives carefully.
• People who don’t care about the environment may face consequences.
• The professor whom we consulted gave us excellent advice.

So… Do We Really Need “Whom”?

In everyday conversation, whom is becoming less common.

However:

• It is still used in formal writing.
• It appears in exams.
• It shows grammatical precision.
• It is common after prepositions in academic English.

So while you may not hear it constantly in casual speech, understanding who vs whom gives you more control over your English — and that’s always a good thing.

Why Do We Need Who and Whom for Cambridge Exams?

In exams such as B2 First (FCE) and C1 Advanced (CAE), understanding the difference between who vs whom can help you write more accurate formal essays and reports. The structure “preposition + whom” is particularly common in advanced writing tasks.

FAQ 

What is the difference between who and whom?
“Who” is used as a subject. “Whom” is used as an object.

Is whom still used in modern English?
Yes, but mostly in formal writing and after prepositions.

Can I say “Who are you talking to?” instead of “To whom are you talking?”
Yes. The first is more natural in everyday conversation. The second is more formal.

Related posts:

Personal and Impersonal Passive

Adverbs in English

Common B2 First Grammar Mistakes to Avoid

How to Write an Essay for B2 First

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