Mastering Defining and Non-defining Relative Clauses

Do you want to make your sentences more complex? Do you want to add more information to your sentences without simply using ‘and’? One effective way to achieve this is by using defining and non-defining relative clauses. These clauses allow you to provide additional information about people, situations, places, times and possessions. 

So, how do you use defining and non-defining relative clauses, and why are they important? 

What are defining and non-defining relative clauses?

Defining relative clauses	Non-defining relative clauses
provide essential information that defines or identifies the noun you are referring to cannot be omitted without changing the meaning of the sentence  e.g. That’s the woman that lives next door. ‘that lives next door’ specifies which woman we are referring to. Removing this would result in an incomplete sentence.	e.g. Janine, who lives next door, is a doctor. ‘who lives next door’ provides additional information about Janine, but does not change the essential meaning of the sentence.  could be omitted without affecting the sentence’s basic structure. i.e. Janine is a doctor.  always separate the clause with a comma both before and after.

Relative pronouns

Defining and non-defining relative clauses rely on relative pronouns to introduce additional information. 

• who refers to people and is used in both defining and non-defining clauses
• which refers to things or animals and is used in both defining and non-defining clauses
• that refers to people, things or animals and is used in defining clauses
• where refers to places
• when refers to times
• whose indicates possession and is used in both defining and non-defining clauses.

How to structure relative clauses 

1. Look at these sentences:
   Today we’re learning about relative clauses. They help us add extra information to a sentence.
   Now look at the same sentences connected by a relative clause.
   Today we’re learning about relative clauses which help us add extra information to a sentence.

Notice that ‘They’ from the second sentence has been removed, and replaced with the relative pronoun ‘which’. This is an example of a defining relative clause.

2. Look at these sentences:
   James is a director. He has worked at the company for six years.
   Now look at the same sentences connected by a relative clause.
   James, who is a director, has worked at the company for six years.

Notice that the sentences are now connected. However, if ‘is a director’ was removed, the sentence would still have meaning – James has worked at the company for six years. 

We are simply adding extra information about James, and have used two commas to separate the information. 

Common mistakes

When using defining and non-defining relative clauses, there are some common mistakes to avoid.

1. It’s important to remember that a comma is used before a non-defining clause, but not before a defining clause.
   Correct: The book, which I read last week, was fascinating. ✔
   Incorrect: The book which I read last week was fascinating. X
2.  ‘that’ should only be used in defining clauses, not non-defining clauses.
   Correct: The movie, which we watched yesterday, was fantastic.✔
   Incorrect: The movie, that we watched yesterday, was fantastic. X 
3. Be careful not to double the subject and the relative pronoun within a defining clause.
   For example:
   Correct: She’s the lady who gave me directions. ✔
   Incorrect: She’s the lady who she gave me directions. X

By using defining and non-defining relative clauses, you can add additional information to your sentences about people, situations, places, times and possessions. It can also make your language more complex in both speaking and in writing. 

What are your top tips for including relative pronouns in your speaking and writing? Share below!

 

Activity 

Choose the correct relative pronoun to complete the sentence. More than one answer may be possible.

1.  That’s the lady _____ talked to me on the plane.
   A. which B. who C. that
2. The company, _____ has been going for over a decade, has moved offices.
   A. who B. that C. which
3. That’s the café _____ we had our first date.
   A. where B. who C. that
4. His dad, _____ worked as a builder, has just retired.
   A. who B. that C. when
5. I was in the kitchen _____ I heard a loud noise.
   A. which B. that C. when
6. He’s someone _____ used to go to school with me.
   A. who B. that C. where

Answers

1. B, who & C, that
2. C, which
3. A, where 
4. A, who
5. C, when 
6. A, who & B, that