Relative Clauses (Who, Which, That)

Master relative pronouns with 26 progressive exercises and 475 practice questions and sentences

Exercises

475

Questions

4-5h

Total Time

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Start with Who vs Which Take Final Test Fix Common Mistakes

All 26 Exercises

Reduced Relative Clauses: Multiple Choice

Multiple choicehard

Choose the -ing, -ed or to-infinitive phrase that replaces a relative clause

20 questions

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Defining and Non-Defining Relative Clauses: Multiple Choice

Multiple choicemedium

Commas or no commas? Decide whether the listener already knows who or what you mean

20 questions

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Who, Which, Whose or Where: Multiple Choice

Multiple choiceeasy

Choose who, which, whose or where by checking the noun and the clause after the gap

20 questions

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Who vs Which

easy

Choose between who (people) and which (things)

20 questions

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That, Whose, Where, When

medium

Practise all relative pronouns in context

20 questions

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All Pronouns Mixed

medium

Choose the correct pronoun from all options

20 questions

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Error Correction

medium

Spot and fix mistakes in complete relative clause sentences

20 questions

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Combining: People

medium

Join sentences about people using who/that

20 questions

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Combining: Things

medium

Join sentences about things using which/that

20 questions

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Combining: Whose & Where

hard

Join sentences using whose (possession) and where (place)

20 questions

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Combining: Mixed

hard

Join sentences using any relative pronoun

20 questions

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Defining Clauses

medium

Essential information without commas

20 questions

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Non-Defining Clauses

hard

Extra information with commas (no 'that')

20 questions

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Defining vs Non-Defining

hard

Distinguish essential from extra information

20 questions

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Subject vs Object + Omission

hard

When can relative pronouns be omitted?

20 questions

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Whom (Formal Object)

hard

Formal object pronoun in writing and speech

20 questions

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Prepositions in Clauses

hard

Formal vs informal preposition placement

20 questions

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Reduced Relative Clauses

hard

Shorten clauses with participles (-ing, -ed)

20 questions

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Mixed Practice - Easy

easy

Review basics: who, which, that, where

20 questions

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Mixed Practice - Advanced

hard

Complex clauses with all features

20 questions

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Final Test

hard

Comprehensive test of all relative clause types

25 questions

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People with Who

Dictationmedium

Practise hearing and writing people with who in complete sentences.

10 sentences

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Things with Which and That

Dictationmedium

Practise hearing and writing things with which and that in complete sentences.

10 sentences

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Places and Times

Dictationmedium

Practise hearing and writing places and times in complete sentences.

10 sentences

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Possession with Whose

Dictationmedium

Practise hearing and writing possession with whose in complete sentences.

10 sentences

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Additional Information

Dictationhard

Practise hearing and writing additional information in complete sentences.

10 sentences

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What are relative clauses in English?

Relative clauses are dependent clauses that give more information about a noun in the main sentence. They begin with relative pronouns (who, which, that, whose, whom) or relative adverbs (where, when, why). Corpus research shows relative clauses appear in approximately 15% of all English sentences, making them essential for fluent communication.

Who / Whom / Whose

For people

"The doctor who treated me was kind."

Which

For things and animals

"The book which I read was fascinating."

That

For people OR things (defining only)

"The house that we bought is beautiful."

Where / When / Why

For place, time, reason

"The city where I was born is small."

What is the difference between who and which?

The rule is simple: use "who" for people and "which" for things and animals. However, "that" can replace both in defining (restrictive) clauses. Corpus analysis shows "that" is actually more common than "who" or "which" in spoken English, especially in American English.

Who = People

"The teacher who teaches math is excellent."

Which = Things

"The book which won the award is now a film."

Which = Animals

"The cat which lives next door often visits us."

That = Both (Defining Only)

"The man that helped me was very kind." / "The car that I bought is red."

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

Defining (restrictive) clauses identify which person or thing we mean - they are essential to the meaning. Non-defining (non-restrictive) clauses add extra, optional information - they use commas and cannot use "that". This distinction is crucial for IELTS and academic writing.

Defining (Essential)	Non-Defining (Extra Info)
No commas	Commas required
Can use "that"	Cannot use "that"
Identifies WHICH one	Adds EXTRA information
"The student who passed got a prize."	"John, who passed, got a prize."
Essential - cannot be removed	Optional - can be removed

Key rule: If the clause identifies the noun (answers "which one?"), it's defining. If it just adds interesting information, it's non-defining. Proper nouns (names) always need non-defining clauses.

When can relative pronouns be omitted?

Relative pronouns can only be omitted when they are the OBJECT of the relative clause. When the pronoun is the SUBJECT, it cannot be omitted. This creates "contact clauses" or "zero relative clauses." Corpus research shows omission is very common in spoken English.

Object pronoun - CAN omit

"The book (which/that) I read was good."-"I" is the subject, so pronoun can go

Subject pronoun - CANNOT omit

"The book won the prize was good."-"which/that" IS the subject - must keep it

Object with people - CAN omit

"The man (who/that) she married is a doctor."-"she" is subject, pronoun can go

Test: If there's a subject AFTER the gap where the pronoun would go, you can omit it. "The book ___ I read" (subject "I" after) = can omit. "The book ___ won" (no subject after) = cannot omit.

How do you use whose in relative clauses?

"Whose" shows possession and replaces his/her/their/its. Unlike who/which, it can be used for both people AND things. It is always followed by a noun (the possessed thing), never a verb. This is a common error for learners.

People

"The man whose car was stolen reported it."

(= his car)

Things

"The house whose roof leaked was repaired."

(= its roof)

Common error: "The woman whose is my teacher..." - WRONG. Whose must be followed by a noun: "The woman whose class I attend..."

When should I use whom instead of who?

"Whom" is the object form of "who," used in formal English. It is required after prepositions: "to whom," "with whom," "for whom." In informal speech, "who" often replaces "whom," and prepositions move to the end. Use "whom" in academic writing and formal contexts.

Formal (with whom)	Informal (who...to)
"The person to whom I spoke was helpful."	"The person who I spoke to was helpful."
"The colleague with whom I work is talented."	"The colleague who I work with is talented."
"The candidate for whom I voted won."	"The candidate who I voted for won."

What are the most common relative clause mistakes?

The most frequent errors are: using "that" in non-defining clauses, omitting subject pronouns, confusing "whose" with "who's," and comma errors. Understanding these mistakes helps you avoid them.

Using "that" in non-defining clauses

"London, that is the capital, is expensive."="London, which is the capital, is expensive."

Omitting subject pronouns

"The man lives here is my uncle."="The man who lives here is my uncle."

Confusing "whose" and "who's"

"The woman who's car is red..."="The woman whose car is red..."

Missing commas in non-defining

"My sister who is 25 works here."="My sister, who is 25, works here."

Frequently Asked Questions

Sources

Research and corpus data referenced on this page:

*
Cambridge Grammar of English - Comprehensive reference for relative clause usage patterns, including defining vs non-defining distinctions.Cambridge Dictionary
*
COCA Corpus Analysis - Research on relative pronoun frequency showing "that" is more common than "who/which" in American English spoken contexts.
*
Swan (2016) - Practical English Usage - Standard reference for relative clause omission rules and contact clause patterns.
*
British National Corpus - Analysis of formal vs informal register differences in relative clause usage, particularly whom vs who.