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A defining clause is essential to identifying its noun and is not set off with commas. An object relative pronoun can often be omitted, but a subject relative pronoun cannot.
| Use | Example | Why it works |
|---|---|---|
| Subject | The person who called is waiting. | You cannot remove who: the verb needs a subject. |
| Object | The book that I borrowed is useful. | I is the subject of borrowed; that is the object. |
| Object omitted | The book I borrowed is useful. | The object relative pronoun can be omitted in this defining clause. |
Check: The person called me is waiting
Use: The person who called me is waiting
Keep a subject relative pronoun in a full defining clause.
Read the example and explain the choice before answering. After the exercise, write a new sentence using the same pattern. Revisit any answer you could not explain, even if you guessed correctly.
4 sets · 40 exercises · about 50–70 minutes with writing and review.
10 scored questions, 20 sentence exercises and 10 writing challenges. Time depends on your pace. Start with the quiz or choose the practice you need.
Your scored quiz and self-reviewed exercises are tracked separately on this device.
Questions 1–5 build confidence; 6–10 check transfer and detail. Use Practice for feedback after each answer, or Test yourself to check at the end.
10 questions · 10 XP per correct answer · explanations included
The book that I bought. In that I bought, I is the subject and that is the object.
who. Who is the subject of live and refers to people.
The bag I bought is blue.. Do not repeat the object as it inside the relative clause.
whose. Whose indicates whose phone it was.
No; it is the subject. That is the subject of stops and must remain.
Students who arrive late must sign in.. Without commas, who arrive late restricts the rule to late students.
that. That introduces a defining clause referring to a thing.
that in “the book that I borrowed”. An object relative pronoun can be omitted. Subject relative pronouns cannot be omitted in these full clauses.
The film we watched was funny.. We is the subject of watched, so the object relative pronoun can be left out.
who. Who is needed as the subject of called and refers to the person.
Complete the missing words, then compare the expected form. More than one natural answer may be possible; use the cue and explanation.
who
The woman who manages the shop is away. (use who)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
that
The bag that I left here is blue. (use that)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
who
People who book early pay less. (use who)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
which
The laptop which has the larger screen is mine. (use which)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
whose
The neighbour whose car was damaged called us.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
where
The room where we practise is upstairs.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
that
The bus that stops here goes downtown. (use that)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
who
Anyone who needs help can ask. (use who)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
which
The course which I chose begins soon. (use which)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
whose
The player whose ankle hurts cannot continue.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
Complete the missing words, then compare the expected form. More than one natural answer may be possible; use the cue and explanation.
where
The café where we usually meet is closed.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
that
The key that opens this door is missing. (use that)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
who
Students who miss the lesson should read the notes. (use who)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
which
The photo which you sent is lovely. (use which)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
whose
The woman whose suitcase was missing found it.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
that
The restaurant that serves noodles is popular. (use that)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
who
The customer who complained wants a reply. (use who)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
which
The house which faces the park is for sale. (use which)
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
whose
The child whose coat is red is my cousin.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
where
The library where I study opens early.
A defining clause identifies which person or thing you mean, normally without commas. Follow the requested pronoun where more than one is possible.
Write an original answer for each task. Review the guidance to check your work. These are self-review tasks, not automatic grammar grading.
Your wording can vary.
Use a defining clause without commas to restrict the group.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Use a relative clause that distinguishes it from other objects.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Keep the subject pronoun in the full relative clause.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
An object pronoun may be omitted when another word supplies the subject.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Use whose plus the possessed noun.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Use where with a full clause.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Omitting a subject relative pronoun leaves a different or incomplete structure.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Use a defining clause without commas to specify only that subset.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Use that inside a defining clause and connect it to a clear noun.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Your wording can vary.
Show a broad group and then a restricted group in your examples.
Check both the form and the meaning. If you are unsure, compare the lesson explanation before marking this exercise reviewed.
Print this lesson’s original questions with a separate answer key. Use the worksheet for another round without looking at the explanations.
Try these two tasks before opening the answers. They practise explanation and writing; they do not change your quiz score.
Can you omit who in The learner who called is waiting? Explain.
No. Who is the subject of called. In the full clause, removing it would leave called without its subject.
Write a defining clause with an object pronoun, then omit that pronoun.
The book that I borrowed is useful. The book I borrowed is useful. I is the subject of borrowed; that is its object and can be omitted here.
Other wording may be correct. Compare the meaning and verb pattern, not just the words.
See how commas change what your sentence means.
Choose the time you have. These are suggested study plans, not timers.
Answer the ten-question quiz. Read the explanation for each mistake before trying again.
Take the scored quiz →30 MINComplete the warm-up, then sets 2 and 3. Compare your answers and correct the patterns you missed.
Open sentence practice →60 MINWork through all four sets. Spend the final part writing, comparing and improving your own sentences.
Explore all four sets →Open the question that matches where you got stuck.
You can omit an object pronoun in a defining clause: “the book that I chose” becomes “the book I chose.” Keep a subject pronoun: “the tutor who helped me.” This omission rule does not apply to non-defining clauses.
Yes: “the file which I saved” and “the file that I saved” can both identify the file. Some style guides prefer that for restrictive clauses. Follow the required style, but do not treat defining which as universally ungrammatical.
Normally, no. They identify the person or thing you mean: “Students who booked can enter.” Adding commas changes the information structure, so punctuation is a meaning choice.
Further reference: British Council: defining relative clauses. Padworth examples and activities are original.
A fresh set of 10 questions with explanations. Continue when you are ready.
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