Grammar Reference

Relative clauses

Meaning and use

Relative clauses are used to give additional information about a noun, such as a person, place or thing. Relative pronouns introduce a relative clause. They include who for people, that and which for things, when for time, and whose to show possession.

 Relative clauses belong to one of two categories: defining relative clauses and non-defining relative clauses.

1. Defining relative clauses add essential information to a sentence.

The woman who found my wallet handed it in to reception.

The student whose dog has run away has gone to look for it.

I remember the day when we first met.

These are the earrings that my mother gave me.

These clauses give essential information about the subject of the sentence. They define the persontime or thing that we are talking about. If we remove the clause, the sentence does not make sense.

2. Non-defining relative clauses add extra information to a noun or noun phrase.

My friend’s birthday, which was last weekend, was great fun.

My current girlfriend, who I love very much, calls me every night.

This extra information is not essential. If we remove the clause, the sentence still makes sense. This type of clause is more common in written English.


Defining relative clauses are made with noun + relative pronoun + rest of clause.

A kangaroo is an animal which lives in Australia.

The man who came for lunch was my uncle.

Winter is a time when it sometimes snows.

Non-defining relative clauses are made in the same way. An important difference, however, between both types of clause, is the use of punctuation. With non-defining relative clauses, we separate the clause with commas. We cannot use that in this type of clause.

My favourite food, which used to be Italian, is now Japanese.

Rachel, who we met yesterday, lives in this neighbourhood.

My car, which I bought seven years ago, needs replacing.

This shirt, which I bought last weekend, cost £50.

My best friend, who I met at university, is coming for dinner.

Take note: replacing the relative pronoun

In informal communication, relative pronouns, such as who and when, are commonly replaced with that in defining relative clauses.

The woman that called last night was very polite.

Do you remember the time that you first met?

Take note: leaving out the relative pronoun

When using defining relative clauses in informal speech and writing, the relative pronoun can be left out completely if it refers to the object of the relative clause.

This is the shirt that I bought.

This is the shirt I bought.

The girl who I like isn’t here yet.

The girl I like isn’t here yet.

In non-defining relative clauses, the relative pronoun cannot be left out.

Take note: spoken English 

The relative pronoun who is used when referring to people. However, in formal written and spoken English, if the pronoun refers to the object of the clause, we use whom instead.

My German teacher, whom I really admired, retired last year.

The woman whom I called this morning was my secretary.