Relative Clauses in English

1. What is a relative clause?

Relative clauses can be used to join two sentences together, or to identify people and things and give more information about them.

• I have a new car. It is a very fast car.
• → I have a new car which is very fast.
• There is a good film on the television tonight. You might like to watch the film.
• → There is a good film on the television tonight which you might like to watch.

2. Types of relative clauses

There are two types of relative clauses: defining and non-defining.

2.1. Defining clauses (Restrictive clauses)

A defining relative clause tells which noun we are talking about. The information is essential in order to understand what or who is being referred to. A defining relative clause usually comes immediately after the noun it describes. We use a relative pronoun (e.g. who, that, which, whose and whom) to introduce a defining relative clause. 

• The film which/that we saw last week was terrible.
• He is the man who/that I met at the party.

Without the defining relative clause we do not know which film or man is being spoken about.

2.1.1 Defining relative clauses:

The relative pronoun can define the subject or the object of the verb:

2.1.2: The relative pronoun is the subject:

We can use the relative pronouns: ‘who’, ‘which’ or ‘that’. We use ‘who’ for people and ‘which’ for things. We can use ‘that’ for people or things.

►The relative clause can come after the subject or the object of the sentence.

►We cannot leave out the relative pronoun from the sentence.

Example 1 (clause after the object of the sentence):

Example 2 (clause after the subject of the sentence):

2.1.3: The relative pronoun is the object:

When the relative pronoun is the object of the clause we can drop the relative pronoun if we want to. Again, the clause can come after the subject or the object of the sentence.

Example 1 (Clause after the object):

Example 2 (Clause after the subject):

3. Non-defining clauses (Non-restrictive clauses)

We use non-defining relative clauses to give extra information about the person or thing. It is not essential information to understand the sentence.

• Jane, who I work with, is getting married.
• I live in Paris, which is a beautiful city.

► We don’t use ‘that’ in non-defining relative clauses. We use ‘which’ if the pronoun refers to a thing, and ‘who’ if it refers to a person.

• Jane, that I work with, is getting married.
• I live in Paris, that is a beautiful city.

► We can’t drop the relative pronoun in this kind of clause.

• Jane, I work with, is getting married.
• I live in Paris, is a beautiful city.

►We put commas around the clause.

Example 1 (Clause comes after the subject):

• My grandmother, who is 99, goes swimming every day

‘who is 99’ is a non-defining relative clause. It adds extra information to the sentence. If we take the clause out of the sentence, the sentence still has the same meaning.

• My son, who is a doctor, lives in Australia
• My bicycle, which is made of carbon, cost a lot of money.

Example 2 (Clause comes after the object):

• Yesterday I called my son, who lives in Australia.
• Last week I bought a new phone, which I don’t know how to use yet.
• I really love the play, which we saw last night.

4. Defining or non-defining relative clauses?