IELTS Grammar: Relative clauses

Relative clauses give information about a noun (or noun phrase). They are linked to the noun (or noun phrase) by a relative pronoun (e.g. who, which). The relative pronoun can be either the subject or the object of the clause, and we do not use another pronoun in the clause to refer to the noun:

Why not install lights which have a timer? (not Why not install lights which they have a timer?)

⚠️We sometimes use a participle clause instead of a relative clause:

the man sitting beside me (= the man who is sitting beside me)
the food kept in the fridge (= the food which is kept in the fridge)

1. Relative pronouns

We use

• Who to refer to people:
  Please welcome Mike Bowers, who is going to talk to us about how to look after your home.

• Which to refer to things:
  These are dangerous if you live in a flat which is in a large high-rise building.
• That to refer to people or things:
  Find someone that can check on your home while you’re away.
  Store away any objects that could become damaging missiles

That is an alternative to who and which and is more common in spoken English.
⚠️That is not used in non-defining relative clauses. (see below)

• where to refer to places:
  This is your home, the place where you keep you keep your most treasured possessions.
• when to refer to times:
  Programme them to come on at times when you would normally be home.
• whose to show possession:
  You’re a person whose job involves a lot of travel.
  He lives in an old house, whose roof needs repairing.
• why after the reason or reasons:
  There are often very good reasons why one house is burgled and another is not.

2. Defining relative clauses

Defining relative clauses give information after a noun to identify the noun more clearly:

Find someone who can collect your mail for you.
Store away any objects that could become damaging missiles if it gets windy. (the relative clause identifies the type of objects)

Without these relatives, it is unclear which person, place or thing we are referring to:
Store away any objects if it gets windy. (we do not know which objects)

We can leave out the relative pronoun when it refers back to the object of the defining relative clause. Compare:

Maybe there’s a neighbour (that) you can ask. (neighbour is the object of the verb)
In the evening, a house that‘s very dark can really stand out. (house is the subject of the verb:
not a house is very dark can really stand out)

3. Non-defining relative clauses

Non-defining relative clauses add extra, non-essential information about something. Compare:

I applied to the university, which is located in the centre of the city. (there is only one university, so its location is extra information: non-defining)
I applied to the university which is located in the centre of the city. (there is another university which is not in the centre of the city: defining)

Non-defining relative clauses are more common in written language than in spoken language.

With non-defining relative clauses:

• We do not use the relative pronoun that:
  The burglars got in through the kitchen window, which the owners had forgotten to shut. (not the kitchen window, that the owners)
• We separate the relative clause from the main clause with commas. There may be two commas or one comma depending on whether the relative clause comes in the middle of a sentence or at the end:
  A letterbox can become full of uncollected letter, which is a great help to a burglar.
  Mr Smith, who was my primary school teacher, got married last week.
• We cannot leave out the relative pronoun:
  My new house, which I have just redecorated, is much larger than my old house. (not My new house, I have just redecorated)
• The relative pronoun can refer to single noun phrase or to a whole clause:
  My neighbour, who lives upstairs, often looks after my flat. (who refers to my neighbour)
  Some people seem to think it’s just a matter of locking all the doors, which is fine as long as there are no nasty storms while you are away. (which refers to the whole of the first phrase)

4. Compare the key differences between defining and non-defining relative clauses:

Defining relative clauses:	Non-defining relative clauses:
– identify the thing that you are talking about – that can replace who or which – the relative pronoun can be left out if it refers to the object – no commas	– give additional, non-essential information – that cannot be used – the relative pronoun cannot be left out – must have commas

5. Prepositions

When prepositions are used with relative clauses they usually come at the end of the clause in spoken English:
You may have a neighbour that you can rely on. (informal)

In formal style the preposition can be placed before the relative pronouns which or whom:
I was unsuccessful in obtaining a place at any of the universities to which i applied.
My boss, for whom I have worked for over 30 years, has decided to retire.

6. Grammar extra: Common collocations with relative pronouns

We often use the expression the one with defining relative clauses:
He’s the one who suggested I became a teacher.
My father is the one that taught me to play the piano.
That house is the one where I grew up.

Wher can be used after expressions such as the situation, the stage or the point:
We were in a situation where there were no easy solutions.
I’m almost at the stage where I’m ready to quit my job and go into business for myself.
I’ve reached the point where I feel I should just give up.