Basic relative clauses (who, which, that)

A relative clause is a mini-clause that tells you more about a noun — who a person is, or what a thing is. Instead of two short sentences, you get one that flows naturally:

The woman lives next door. She teaches music. → The woman who lives next door teaches music.

Once you have this structure, you can describe people, places and things in one smooth sentence instead of several choppy ones.

The quick version: use who for people, which for things, and that for either. Place the relative clause immediately after the noun it describes.

Who, which or that?

The pronoun you use depends on what you are describing:

In defining relative clauses (the kind without commas that narrow down which person or thing you mean), that can often replace who or which: the woman that called, the book that I bought. At this stage, that is usually a safe choice. Avoid it after a preposition (the house in which I grew up, not ❌ the house in that I grew up) and in comma relative clauses — but those are topics for later.

The structure: noun + pronoun + clause

A relative clause sits immediately after the noun it describes:

[noun phrase] + who / which / that + [rest of the clause]

• That's the teacher who taught me French.
• Is this the bus that goes to the airport?
• I love the jacket which you were wearing yesterday.
• The café that we went to last week is closed now.

The relative clause needs to sit right after the noun it describes. If there is a relative pronoun, it comes at the start of that clause. Letting it drift to the end breaks the connection: ❌ The teacher taught me French who was very strict. → ✅ The teacher who taught me French was very strict.

Subject relative clauses

When who / which / that is the subject of the relative clause (it performs the action), the pronoun is essential — you cannot leave it out:

• the film that won the award — that won (it's the subject)
• the colleague who helped me — who helped (she's the subject)
• a dog that barks all night — that barks (it's the subject)

Object relative clauses — and leaving the pronoun out

When who / which / that is the object of the relative clause — whether the object of a verb or the object of a preposition — there is already a separate subject (I, we, she, etc.):

• the film that I recommended — I recommended it; that is the object
• the colleague who I called — I called her; who is the object
• the bag which she bought — she bought it; which is the object
• the keys that you were looking for — you were looking; that is the object of for
• the café that we went to — we went; that is the object of to

In these cases you can drop the pronoun entirely — this is very natural in everyday English:

A useful guide: in a simple sentence, if the relative pronoun is followed by a subject like I, you, we, or a noun, it is likely an object relative — you can usually leave the pronoun out. If the pronoun itself performs the action with nothing else to fill that role, keep it.

A note on places

For places, English often uses where to mean "in / at which place": the café where we met, the city where I grew up. With that or which, keep the preposition: the café that we met in / the café we met in. At this stage, where is the easiest choice.

Common mistakes

• ❌ She is the doctor which treated me. → ✅ She is the doctor who treated me. (use who for people, not which)
• ❌ That's the book who I told you about. → ✅ That's the book that I told you about. (use which or that for things)
• ❌ The man who he lives next door is a chef. → ✅ The man who lives next door is a chef. (who already fills the subject role — adding he repeats it)
• ❌ Is this the restaurant that it was on TV? → ✅ Is this the restaurant that was on TV? (that is already the subject — the extra it is not needed)
• ❌ I found the book that I bought it. → ✅ I found the book that I bought / the book I bought. (the relative pronoun already stands for it — don't add it again)

Quick check

Complete each sentence with who, which, or that. If the pronoun can be left out, put it in brackets.

1. That's the woman ____ works with my sister.
2. The laptop ____ I bought last year has stopped working.
3. Is that the film ____ won five Oscars?
4. I found the keys ____ you were looking for.

Key takeaways

• A relative clause adds information about a noun and comes immediately after it.
• Who → people; which → things; that → people or things (safe default).
• Structure: noun + who / which / that + clause.
• If the pronoun is the subject of its clause (nothing else can do the action), keep it.
• If the pronoun is the object (there's already a subject after it), you can drop it: the film I recommended = the film that I recommended.
• Avoid repeating the noun with an extra pronoun: ❌ the man who he lives next door → ✅ the man who lives next door; ❌ the book that I bought it → ✅ the book that I bought / the book I bought.