Relative clauses: defining relative clauses

Relative clauses: defining relative clauses

Do you know how to define who or what you are talking about using relative clauses? Test what you know with interactive exercises and read the explanation to help you.

Look at these examples to see how defining relative clauses are used.

Are you the one who sent me the email?
The phone which has the most features is also the most expensive.
This is the video that I wanted to show you.
The person they spoke to was really helpful.

Try this exercise to test your grammar.

Grammar test 1

Grammar B1-B2: Relative clauses – defining relative clauses: 1

Read the explanation to learn more.

Grammar explanation

Relative clauses give us information about the person or thing mentioned. 

Defining relative clauses give us essential information – information that tells us who or what we are talking about.

The woman who lives next door works in a bank. 
These are the flights that have been cancelled.

We usually use a relative pronoun or adverb to start a defining relative clause: who, which, that, when, where or whose.


We can use who or that to talk about people. that is more common and a bit more informal.

She's the woman who cuts my hair.
He's the man that I met at the conference.


We can use which or that to talk about things. that is more common and a bit more informal.

There was a one-year guarantee which came with the TV.
The laptop that I bought last week has started making a strange noise!

Other pronouns

when can refer to a time.

Summer is the season when I'm happiest.

where can refer to a place.

That's the stadium where Real Madrid play.

whose refers to the person that something belongs to.

He's a musician whose albums have sold millions. 

Omitting the relative pronoun

Sometimes we can leave out the relative pronoun. For example, we can usually leave out who, which or that if it is followed by a subject.

The assistant [that] we met was really kind.
   (we = subject, can omit that)

We can't usually leave it out if it is followed by a verb.

The assistant that helped us was really kind.
   (helped = verb, can't omit that)

Do this exercise to test your grammar again.

Grammar test 2

Grammar B1-B2: Relative clauses – defining relative clauses: 2

Language level

Average: 4.2 (71 votes)

Hi Hieu Nguyen,

We can omit "when", but not "where". However, omitting "where" is sometimes done in the phrase "the place (where)", e.g. "If we go back to the place (where) we started, we'll find the right way." or "I tried to find the place (where) I met her but I couldn't find it again."

I hope that helps.

The LearnEnglish Team

Hello Mr. Jonathan R,

Thank you for your answer! However, for me, "the place" can replace "the stadium" in the example:

> That's the place/the stadium where Real Madrid play.

Then why can't we leave out "where" in that example? Is this some kinds of conventions in English?

Also, is it acceptable that we omit "when", "why" or "where" when possible in more formal contexts (like in writing)?

Hieu Nguyen

Hi Hieu Nguyen,

If you only look at the structure of the sentence, then yes - "the place" can replace "the stadium". But language use is not only a matter of structure/grammar. Words have individual characteristics too, including how they combine with other words in common phrases, and these cannot be described with grammatical rules. For whatever reason, it has become relatively common to omit "where" after "the place", but not after "stadium" or other words denoting places. It's a matter of vocabulary usage too, not only grammar.

Yes, it is acceptable to omit relative pronouns in formal writing. However, in more precise writing (e.g. technical reports or legal writing, or when you just want to express yourself clearly), it may be better not to omit them, to ensure maximum clarity of meaning. (Precise writing is not always formal writing.)

I hope that helps.

The LearnEnglish Team

Hello again Mr. Jonathan R,

Thank you for your detailed explanation. I get it now.

Hope you have a good day, sir.

Submitted by chicavampiroruarrr on Mon, 17/01/2022 - 15:22


Dear Kirk, first of all, my class and I love your name and we think you’re very slayyyy! But your exercises aren’t done correctly, because it only shows a certain number of questions to different people. I got 10 questions out of 16, my friend got 8 questions out of 16 and my other classmate got 13 questions out of 16. Please fix your error.
Thank you for your attention, xoxo 💋

Hello chicavampiro,

I'm glad to hear it!

Regarding your question, in each exercise, you have to choose 16 options (this is what '16 items remaining' means), so the questions can have one, two, or three correct options.

For example, in Grammar test 1, for the first sentence, 'who' and 'that' are both correct; for the second sentence, 'who', 'that' and '–' are correct. You have to tick the boxes for all of these answers.

You can also see the correct answers: after you press the 'Finish' button, press the 'Show answers' button to see them.

Hope this helps you and your friends and classmates.

Best wishes,
The LearnEnglish Team

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Submitted by haovivu128 on Thu, 16/09/2021 - 10:31

Hello sirs, Could you help me correct them? Thank you in advance. Defining relative clauses: *0 = no relative pronoun. 1. who (subject): That's the man who/that teaches me Math subject at the school. 2. who/whom (object): The man who/whom/that/0 I admire the most is my father. 3. which (subject): The books which/that are the bestsellers over the world are the “Harry Potter” Novels. 4. which (object): Where are the tickets which/that/0 I bought yesterday? 5. whose (human): That’s Justin whose sister works at the office with me. 6. whose (animals; things): These are rooms whose equipments are used for the particular activities. 7. where (places): The place where we got married is Notre Dame Catheldral Church. 8. when (times): We’re going to remember the moments when we stayed together.

Hi haovivu128,

You did a good job :) The relative pronouns and relative clauses are correct. But I do have a few other corrections:

  • 1: instead of 'Math subject', it should just be 'Math' (or 'Maths').
  • 3: It should be 'bestsellers', without 'the' before it.
  • 6: 'equipment' should be uncountable, not countable (so the verb should be 'is', not 'are').

I hope that helps.


The LearnEnglish Team

Submitted by BobMux on Tue, 20/04/2021 - 16:44

Hello the LearnEnglish Theam, Could you please help me understand defining relative clause better. Here is the sentence: A substance in the tank which is used by the farmers ... Is the tank used by farmers or is the tank?