Relative Clauses: Using Who, Which and That

Imagine three people waiting outside a classroom. “Speak to the woman” may not tell your friend enough. “Speak to the woman who is holding a green folder” identifies the person. The words beginning with who form a relative clause. They add information about a noun without forcing you to start a separate sentence.

Choose who, which or that

Use who for people and which for things. In a defining relative clause, which tells us the person or thing you mean, that can often replace either word. Start with these three patterns before exploring whose, where or more formal constructions.

The relative clause usually follows the noun it describes. Keep the connection close: “I found the bag that you left in the café.” If you move the clause too far away, the reader may connect it to the wrong noun. For more descriptive vocabulary, revisit describing people and places.

Join two ideas without repeating a word

Start with two sentences: “A neighbour helped us. The neighbour lives next door.” Combine them as “The neighbour who lives next door helped us.” Who stands for the neighbour inside the relative clause. Do not write “The neighbour who he lives next door.” The extra he repeats the same subject.

Try a thing: “I bought a lamp. The lamp uses very little electricity.” This becomes “I bought a lamp which uses very little electricity.” That also works here. Keep the original meaning when you combine sentences; the relative clause should identify or describe the same person or object.

Know when the relative word can disappear

Compare “The friend who called me is here” with “The friend who I called is here.” In the first sentence, who does the calling. It is the subject of the relative clause and must stay. In the second, I do the calling and who refers to the person receiving the call. You can say “The friend I called is here.”

The same distinction works with things: “The cake that won the prize” needs that, but “The cake that we made” can become “The cake we made.” If you are unsure, keep who, which or that while you check the pattern. Avoid adding an extra object: “The cake that we made it” repeats the cake.

Keep defining clauses separate from extra information

This lesson mainly uses defining clauses: information that helps identify which person or thing you mean. They do not normally have commas around them. “The students who arrived early set up the chairs” identifies the early arrivals, rather than necessarily describing every student.

Extra-information clauses use commas: “Our tutor, who arrived early, set up the chairs.” Here the tutor is already identified. In this kind of clause, use who or which rather than that, and keep the relative word. The British Council relative-clause reference explains the distinction in more detail.

Read and write with the noun in mind

When reading, find the noun before the relative word and ask what the clause adds. In “The path that runs behind the school is closed,” the clause identifies the path. The main message is that the path is closed. This approach connects with using context clues: nearby information helps you understand the sentence.

For writing practice, choose three objects in your room. Describe each without naming it: “It's something that keeps my drink warm.” Ask a partner to guess. Then choose one description and check the noun, relative word and verb. If the sentence only needs a simple link between whole ideas, and, but, because and so may be a better fit than a relative clause.