Skip to content

Grammar Exercises

Relative Clauses: Who, Which, That + 30 Exercises With Answers

A relative clause is a dependent clause that describes a noun, usually introduced by a relative pronoun (who, which, that, whose, whom) or a relative adverb (where, when, why), as in the woman who lives next door or the town where I grew up.

Written by Raheel AshrafAbout 15 min read

Free practice: Free English grammar exercises online (with answers)

A relative clause is a dependent clause that gives information about a noun. It comes right after the noun and starts with a relative word: who for people, which for things, that for people or things, whose for possession, and where, when, or why for places, times, and reasons. Examples: The man who called is my uncle. The phone that I bought is broken. That's the café where we met.

Relative clauses are either defining (they identify which person or thing you mean, with no commas) or non-defining (they add extra information, with commas). The 30 exercises below cover choosing the right relative word, the comma rule, when that is not allowed, when you can leave the pronoun out, and where the preposition goes.

Relative Clauses Quiz: 30 Questions

Warm-up · choose the relative word

1.The woman ___ lives next door is a nurse.
2.I lost the keys ___ you gave me.
3.That's the café ___ we first met.
4.He's the author ___ books have sold millions.
5.I remember the summer ___ we drove to Spain.
6.Identify the relative clause: 'The film that we watched last night was long.'
7.Which relative pronoun is used for things and animals?
8.The student ___ essay won the prize is in my class.
9.Which word can replace 'which' in this defining clause? 'The phone which I bought is broken.'
10.The children, ___ were tired, fell asleep in the car.

Core · defining vs non-defining, commas, omission

11.Is the relative clause defining or non-defining? 'My mother, who is a teacher, loves reading.'
12.'Students who finish early may leave.' The relative clause is…
13.There is only one Eiffel Tower. Which sentence is correct?
14.In which sentence can you leave out the relative pronoun?
15.Which sentence is NOT correct?
16.Tokyo, ___ is the capital of Japan, is huge.
17.The hotel ___ we stayed was lovely.
18.Choose the option that is correct in formal English: 'The person to ___ I spoke was helpful.'
19.Which version is correct? 'This is the house ___.'
20.'I passed the exam, which surprised everyone.' What does 'which' refer to?

Challenge · meaning, whom, and prepositions

21.What does this sentence suggest? 'My sister who lives in Leeds is a doctor.' (no commas)
22.What do the commas tell you? 'My sister, who lives in Leeds, is a doctor.'
23.Which sentence is correct?
24.The company, ___ profits fell last year, is cutting jobs.
25.Which sentence uses 'whom' correctly?
26.In a defining clause about a thing, which word do US style guides generally prefer? 'The report ___ I sent you is outdated.'
27.Which sentence is punctuated correctly?
28.Prepositions in relative clauses: which sentence is NOT correct?
29.Do you know the reason ___ she left?
30.Which sentence correctly reduces 'The man who is standing by the door is my boss'?
Answer key and explanationsOpen after you finish the quiz.
  1. 1. whoWoman is a person, and the gap is the subject of lives, so who is correct (that would also work). Which is for things, whose shows possession, and where is for places.
  2. 2. whichKeys are things, so which is correct; that, or no pronoun at all, would also work in this defining clause. Who is only for people, and whose needs a noun after it.
  3. 3. whereWhere means at which and introduces a clause about a place. Which on its own would need a preposition (the café at which we first met), and who and whose do not fit a place.
  4. 4. whoseWhose shows possession (the author's books) and is followed directly by a noun. Who's is a contraction of who is or who has, so who's books is wrong.
  5. 5. whenSummer is a time, so the relative adverb when (meaning in which) introduces the clause. Where is for places, whose for possession, and who for people.
  6. 6. that we watched last nightThe relative clause starts with the relative pronoun that and runs to the end of the description: that we watched last night. It tells us which film, and the main clause is the film was long.
  7. 7. whichWhich refers to things and animals; that can also be used in defining clauses. Who and whom refer to people, although pets are sometimes referred to with who.
  8. 8. whoseThe essay belongs to the student, so you need the possessive whose, followed directly by the noun essay. Who and whom cannot show possession.
  9. 9. thatIn defining clauses, that can replace which (for things) or who (for people). What is never a relative pronoun after a noun: the phone what I bought is non-standard.
  10. 10. whoThe commas mark a non-defining clause, and that cannot introduce a non-defining clause. Children are people, so use who.
  11. 11. Non-definingYou have only one mother, so who is a teacher does not identify her; it adds extra information. Extra-information clauses are non-defining and are set off with commas.
  12. 12. defining: it tells us which studentsOnly the students who finish early may leave, so the clause identifies a group and is essential to the meaning. Defining clauses take no commas.
  13. 13. The Eiffel Tower, which was built in 1889, attracts millions.A unique noun does not need identifying, so the clause is non-defining: commas plus which. That cannot introduce a non-defining clause, and without commas the sentence suggests there is more than one Eiffel Tower.
  14. 14. The book that I'm reading is great.In the book that I'm reading, that is the object (I'm reading it), so it can be dropped: the book I'm reading. In the other sentences the pronoun is the subject of the clause and must stay.
  15. 15. The car, that I bought, is red.Commas make the clause non-defining, and that is not used in non-defining clauses. The other three are all correct defining clauses: with that, with which, or with the object pronoun left out.
  16. 16. whichTokyo is unique, so the clause adds extra information and needs which inside commas. That is not allowed in non-defining clauses, and where would need a subject of its own (where 14 million people live).
  17. 17. whereStay needs a preposition before a place (stay at a hotel). Where includes that meaning (at which); which or that would need at: the hotel which we stayed at.
  18. 18. whomDirectly after a preposition, formal English uses whom for people and which for things. That can never follow a preposition, and to who is common in speech but not accepted in formal writing.
  19. 19. in which I grew upIn which I grew up puts the preposition before which, a formal and correct pattern. That cannot follow a preposition, where already contains the meaning of in, and which I grew up is missing in.
  20. 20. The whole idea that I passed the examHere which refers back to the whole main clause: my passing surprised everyone, not the exam itself. This kind of clause is always non-defining, takes a comma, and cannot use that.
  21. 21. I have more than one sister, and this one lives in Leeds.Without commas the clause is defining: it picks out one sister from several. If you have only one sister, add commas: My sister, who lives in Leeds, is a doctor.
  22. 22. The clause adds extra information about a sister already identified.Commas make the clause non-defining: the reader already knows which sister, and who lives in Leeds is extra detail. Removing the commas would change the meaning to one sister among several.
  23. 23. Everything that he said was true.After everything, all, nothing, and something, use that (or leave it out: everything he said). What is not used as a relative pronoun after a noun or pronoun, and who refers to people.
  24. 24. whoseThe profits belong to the company, so use whose; it works for organizations and things as well as people. That and which cannot show possession, and who's means who is.
  25. 25. The man whom I met yesterday is an architect.Whom is an object form: I met him, so the man whom I met. In the other two, the pronoun is the subject of lives and is, so the correct form is who.
  26. 26. thatUS style guides generally prefer that for defining (restrictive) clauses and keep which for non-defining ones. Which in a defining clause is also grammatical and common, especially in British English.
  27. 27. My laptop, which is five years old, still works.A non-defining clause needs a comma on both sides, like brackets. The first two options are each missing one comma, and the last uses that, which is not allowed in non-defining clauses.
  28. 28. This is the song about that I told you.The preposition can go at the end (informal) or before which or whom (formal), but never before that. About that I told you is therefore wrong.
  29. 29. whyAfter reason, use the relative adverb why (or that, or nothing: the reason she left). Which would need for (the reason for which), and where and whose do not fit.
  30. 30. The man standing by the door is my boss.You can reduce a relative clause by dropping both the pronoun and be: who is standing becomes standing. Dropping only one of them leaves an ungrammatical sentence.

Who, Which, That, Whose, Whom, Where, When

A relative clause begins with a relative pronoun or relative adverb that points back to the noun before it. The choice depends on whether the noun is a person, thing, place, time, or reason, and on the job the word does inside the clause.

  • who: people, as subject or (informally) object. The nurse who helped me was kind.
  • whom: people, as object, mainly formal and after prepositions. The client whom we met / to whom I wrote.
  • which: things and animals. The bike, which I bought last year, is broken.
  • that: people or things, in defining clauses only. The bike that I bought is broken.
  • whose: possession, for people and things. The writer whose novel won / the house whose roof leaks.
  • where: places (= in/at which). The village where she was born.
  • when: times (= in/on which). The year when we met.
  • why: after reason (= for which). The reason why he left.

What is not a relative pronoun after a noun. Write the thing that I need or the thing I need, not the thing what I need.

Defining vs Non-Defining Relative Clauses

A defining (restrictive) relative clause tells you which person or thing the speaker means. Remove it and the sentence loses essential meaning. It takes no commas: The people who live upstairs are noisy.

A non-defining (non-restrictive) relative clause adds extra information about a noun that is already identified. Remove it and the main meaning stays the same. It is set off with commas (or dashes or brackets): My neighbour, who works nights, is very quiet.

  • Defining: The students who passed got certificates. (only those students)
  • Non-defining: The students, who passed, got certificates. (all the students passed)
  • That is used only in defining clauses, never in non-defining ones.
  • Proper nouns and unique things (Paris, my mother, the sun) normally take non-defining clauses.
  • Which referring to a whole clause is always non-defining: He was late again, which annoyed everyone.

Comma test: can you put the clause in brackets without changing the meaning? If yes, it is non-defining and needs commas.

When You Can Leave Out the Relative Pronoun

In a defining clause, you can omit who, which, or that when it is the object of the clause, that is, when another subject follows it. You cannot omit it when it is the subject, or in any non-defining clause.

  • Object, can omit: The book (that) I'm reading is long.
  • Object, can omit: The woman (who) we met is a pilot.
  • Subject, must keep: The woman who met us is a pilot.
  • Non-defining, must keep: The book, which I'm reading now, is long.
  • Reduced clause: drop the pronoun and be together: The man (who is) sitting there is my boss.

Quick check: if a noun or pronoun comes straight after who, which, or that (that I, who we), the relative pronoun is the object and can usually be dropped.

Prepositions in Relative Clauses, and Which vs That

A preposition can go at the end of the relative clause, which is natural in everyday English, or in front of which or whom, which is more formal. It can never go in front of that or who.

In defining clauses about things, both which and that are grammatical. US style guides generally prefer that for defining clauses and reserve which for non-defining ones, and many American editors apply that preference consistently. Which in defining clauses is common and correct, especially in British English. In non-defining clauses, only which works in both varieties.

  • Informal: the person I spoke to / the job she applied for
  • Formal: the person to whom I spoke / the job for which she applied
  • Wrong: the person to who I spoke / the job for that she applied
  • US preference: The report that I sent you is outdated.
  • Also correct, more common in UK English: The report which I sent you is outdated.

Keep practicing

Frequently Asked Questions

What is a relative clause example?

The woman who lives next door is a nurse. Who lives next door is the relative clause: it describes woman and begins with the relative pronoun who. Other examples: the book that I lent you, the city where I was born, my brother, whose car I borrowed.

What is the difference between defining and non-defining relative clauses?

A defining clause identifies which person or thing you mean and has no commas (The car that I bought is red). A non-defining clause adds extra information about something already identified and is set off with commas (My car, which is red, is new). That can only be used in defining clauses.

Can you use 'that' instead of 'which'?

Yes in defining clauses: the phone that I bought and the phone which I bought are both correct, and US style guides generally prefer that. No in non-defining clauses: My phone, which is new, is broken cannot use that.

Check Your Relative Clauses and Commas

PromGee's free grammar checker can flag missing commas around non-defining clauses, sentence fragments, and run-ons, and explains each suggestion. Paste your writing to review the fixes.

Check My Writing Free

Sources & References

Keep reading: more grammar guides