Defining relative clauses (also known as restrictive relative clauses) identify a noun more clearly. They make it clear which specific person or thing we are talking about.
Example:
The man is my brother.
This sentence is not clear because there are 2 men. Which man is my brother? We use a defining relative clause to make it more clear:
The man who is standing is my brother.
The underlined text “who is standing” is the defining relative clause. It defines more precisely the “man”. That is why it is called a “defining relative clause.” It narrows down a large group to a clearly defined one.
Relative clauses are good because they allow us to write complex sentences.
Relative pronouns
Relative pronouns are part of the relative clause. We link the relative clause to the noun with a relative pronoun.
There are 5 relative pronouns as follows:
who
whom
which
that
whose
Let’s look at each one in more detail.
who
We use “who” for people only. It acts as the subject pronoun.
Example:
The customer who called me was happy. (subject pronoun)
In modern English, “who” is also commonly used as an object pronoun.
Example:
The customer who I called was angry. (object pronoun)
However, it should be noted that in strict English grammar, “who” is only used as a subject pronoun. In more formal English, “whom” is used as an object pronoun.
whom
We use “whom” for people only. It acts as the object pronoun.
Example:
The customer whom I called was angry. (object pronoun)
“whom” is only really used in very formal English. It is more common to use “who” as the object pronoun for people.
“who” and “whom” are often replaced by “that” in spoken English (see below).
which
We use “which” for things or animals. “which” acts as a subject or object pronoun.
Examples
It’s a book which will interest you. (subject pronoun)
The car which he bought was expensive. (object pronoun)
“which” is often replaced by “that” in spoken English (see below).
that
We use “that” for people or things. “that” acts as a subject or object pronoun.
Examples with people:
The customer that called me was angry. (subject pronoun)
The customer that I called was happy. (object pronoun)
Examples with things:
It’s a film that scared us. (subject pronoun)
The dress that she was wearing was beautiful. (object pronoun)
“that” is very common in spoken English.
whose
We use “whose” for people or things. “whose” acts as a possessive pronoun. This means it defines who owns something or someone (who is the parent of someone).
Examples:
I know a man whose daughter lives in New York.
(The daughter of the man lives in New York.)
Jane works in a restaurant whose manager is never there.
(The manager of the restaurant is never there.)
Position of prepositions in a defining relative clause
There are 2 choices for the position of prepositions:
- before the relative pronoun (formal)
- at the end of the relative clause (informal)
Examples:
I like the people with whom I work. (formal)
I like the people that I work with. (informal)
That is the flat in which my parents live. (formal)
That is the flat which my parents live in. (informal)
“who” or “that” are not used after prepositions:
I like the people with who I work. 
That is the flat in that my parents live.
Omission of the relative pronoun
The relative pronoun can be omitted when it is the object of the clause. This is optional. We can leave it in if we want.
Examples:
The customer who I called was very happy. 
The customer I called was very happy.
He is eating the sandwich that you made.
He is eating the sandwich you made.
When the relative pronoun is the subject of the clause, it cannot be omitted. We must leave it in.
Examples:
The customer who called me was angry.
The customer called me was angry.
Punctuation rule with defining relative clauses
We do not use commas (,) to separate the relative clause from the rest of the sentence when writing defining relative clauses.
It’s a book which will interest you.
It’s a book, which will interest you.
The girl who is talking to Mark is my sister.
The girl, who is talking to Mark, is my sister.
We only use commas when writing non-defining relative clauses.
More English lessons
IELTS preparation and writing practice
Private online English lessons with a native speaker
Non-defining relative clauses
Reflexive pronouns and intensive pronouns
Personal pronouns in English
English prefixes
Present perfect verb tense in English
Nurat says
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