Defining & Non-Defining Relative Clauses
In this lesson you will learn everything you need to know about Defining & Non-Defining Relative Clauses, such as when to substitute the relative pronoun with “that” and when to omit it. You can check your comprehension with the exercises below. If you need to revise relative pronouns, check out this class here. This lesson is part of a complete B2 grammar course.
Look at these three sentences.
This is a presentation which you might find useful.
This is a presentation that you might find useful.
This is a presentation you might find useful.
They all mean the same thing. One of them uses “which“, one of them uses “that” and one of them uses neither “which” nor “that”. In this lesson you will learn when and how to substitute or omit this kind of word.
Contents
- What are relative pronouns and relative clauses?
- What are dependent and independent relative clauses?
- When can we substitute and omit relative pronouns?
- Exercises
What are relative Pronouns and Clauses?
What are Relative Pronouns?
- Who – people
- Which – things
- Where – places
- Whose – owners of things
- When – times
- What / that
What is a clause?
A group of words that contain a subject and a verb that works as an independent sentence.
Examples of Clauses
She was worried that you had lost the details.
Did you know that the shop closes at 7?
This isn’t the first time that he has broken the law.
What are Relative Clauses?
Relative clauses are clauses that start with a relative pronoun.
That’s the boy who sold me the bicycle.
The airport, which was built in 1982, is busier than ever.
Comparing defining and non-defining relative clauses.
Non-defining relative clauses.
A non-defining relative clause provides extra or non-essential information.
The sentence below contains a non-defining relative clause.
The Mona Lisa, which was painted by Da Vinci, is worth millions.
“which was painted by Da Vinci” is extra information and can be omitted.
Extra information / non-defining relative clauses are usually after or between commas.
The sentence would still make sense without the relative clause.
The Mona Lisa is worth millions.
Defining relative clause
A defining relative clause is the definition of the object of the sentence.
She’s the woman who lives next door to my aunt.
“Who lives next to my aunt” is the definition of the who the woman is. The sentence doesn’t make sense without this clause.
She’s the woman.
Why is this difference important?
The difference between these types of sentence is important for two reasons;
it can change the meaning of the sentence.
In defining relative clauses you can substitute “who” or “which” with “that” or sometimes omit the relative pronoun completely. In non-defining relative clauses we cannot substitute “which” or “who” for “that” or omit the relative pronoun.
You can practise identifying defining and non-defining relative clauses with this exercise here.
A slight difference in meaning.
My brother, who lives in Australia, is older than me.
In this sentence, “who lives in Australia” is extra information. We cannot tell how many brothers this person has from this sentence. Maybe 1, maybe more!
My brother who lives in Australia is older than me.
In this sentence, “who lives in Australia” is the definition of which brother the sentence refers to. This gives the impression that the speaker has multiple brothers.
Substitution in Defining Relative Clauses
In defining relative clauses we can substitute which or who with that.
These examples are synonymous.
He’s the man who wrote the song.
He’s the man that wrote the song.
Here, “that” is used instead of “which”.
That’s the dog which bit me.
That’s the dog that bit me.
Note: American English tends to have a preference for “that” instead of “which”, but both are correct.
Omission of Relative Pronouns in defining relative Clauses
She’s the woman who I told you about yesterday.
She’s the woman that I told you about yesterday.
She’s the woman I told you about yesterday.
Omission of Relative Pronouns – The Rule
We cannot omit the relative pronoun if it is the subject of the relative clause.
We can omit the relative pronoun if it is the object of the relative clause.
If the relative pronoun is “doing” the verb, you can’t omit it.
Omission of Relative Pronouns – Examples
In this example a sentence (a defining relative clause) is given with which, that and finally without the relative clause.
In this example it is possible to omit the relative clause because “the book” is not the subject of the relative clause (I lent you).
Did you read the book which I lent you?
Did you read the book that I lent you?
Did you read the book I lent you?
In this example, it is not possible to omit the relative pronoun because “the man” is both the object of the first clause and the subject of the second clause.
He’s the man who won the competition.
He’s the man that won the competition.
You can practise substitution and omission of relative pronouns in this exercise.
Things to Remember
In defining relative clauses we can substitute Which or Who for That.
We cannot omit the relative pronoun if it is the subject of the relative clause.
Exercises
Check that you understand how to use this grammar with these interactive exercises.