Grammar for IELTS: A Look at Relative Clauses

September 26, 2019 by Andrea Castro

Even though there’s no actual grammar test section in IELTS, your use of English grammar plays a key role in getting a high IELTS score. Grammar is one of the four categories that you will be assessed on in the Writing and Speaking modules of the IELTS. Examiners will focus on both your grammatical range (whether you can use a variety of simple and complex grammatical structures) and accuracy (whether your language has errors). Because using a range of structures in an accurate way can increase your chances at achieving a higher score, this Grammar for IELTS series will explore more complex grammatical structures that you can use on your IELTS. Today we’ll look at relative clauses. 

What is a clause? 

To better understand what relative clauses are and how to use them, let’s start by talking about what the term clause means in grammar. Essentially, a clause is a group of words that contain a verb. Clauses can be independent or dependent. While an independent clause is a simple sentence that can stand alone (e.g. I grew up in Delhi.), a dependent clause is a group of words that also contains a subject and a verb, but it does not express a complete thought (e.g. where I grew up).

What are relative clauses, and how do we use them?

Relative clauses are used to describe or give extra information about something that has already been mentioned (e.g. The movie, which stars Nicole Kidman, was released in the '90s.)

We often use relative pronouns (usually who, where, when, that, which, whose) to introduce relative clauses. The relative pronoun we use depends on what we are referring to and the type of relative clause.  


people and sometimes animals

defining and non-defining


animals and things

defining and non-defining; clause referring to a whole sentence


people, animals and things (informal)

defining only


possessive meaning (for people and animals usually, sometimes for things in formal situations)

defining and non-defining


people in formal conversations or in writing; often with a preposition; used instead of who if who is the object

defining and non-defining



defining and non-defining



defining and non-defining



defining only

Relative clauses are divided into two types: defining relative clauses and non-defining relative clauses. We use defining relative clauses to give essential information that we need in order to understand what or who is being referred to. They usually come immediately after the noun it describes (In the examples, the person/thing being referred to is underlined, and the relative clause is in bold.):

  • There are many regions where the effects of global warming can already be seen.
  • They’re the people who can actually help.
  • The book is about a woman whose son went missing.

In defining relative clauses, we can leave out the relative pronoun when it is the object of the verb:

  • Mondays are usually the days (when) I feel the most stressed out.
  • They were the only locals (who/that) I talked to during my trip.
  • Those were some of the health risks (that) the scientists identified.

We use non-defining relative clauses to give additional information about the person or thing. However, we don’t need this information to understand who or what is being referred to, because it is not essential information:

  • My grandfather, who passed away 4 years ago, was a very successful businessman.
  • Unlike other popular beaches in the area, which are usually crowded and chaotic, Santa Teresa is a quiet beach with beautiful views.
  • Antonio, whose family fled a civil war in their country, wrote a book about the challenges of being an immigrant.

 As you may have noticed, in writing, we don’t use commas in defining relative clauses, but we do in non-defining relative clauses. In speaking, we often pause at the beginning and end of non-defining relative clauses.

Improving your use of relative clauses

IELTS Girl Reading
If you feel like you need more practice in order to master the use of relative clauses for your IELTS, here are some tips to help you achieve your IELTS goals:

  • Use grammar books or online grammar resources to practice relative clauses by completing grammar exercises.
  • When reading English texts, look carefully at how sentences are structured.
  • Try using relative clauses when communicating in English with family, friends or co-workers.
  • If you notice you have lots of short, simple sentences in your writing, try using more relative clauses to combine some of the sentences.

Stay tuned for our next grammar post on the passive voice!

Andrea is an experienced English teacher who has worked since 2009 in Costa Rica, Dubai and now Canada. When not working for IELTS, she spends her time with her little girl and her two canine siblings.

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