IELTS HUB
Grammar for IELTS · Lesson 1

Using Relative Clauses Effectively

Learn to use relative clauses to add detail and sophistication to your IELTS writing, enhancing clarity and coherence for higher scores.

Band 7+ Advanced Writing 15 min 40 questions
HS

Hardev Singh Sra Author, IELTS expert

Topic introduction

Relative clauses add specific information about a noun (or noun phrase), typically introduced by relative pronouns (e.g., who, which, that, whose) or relative adverbs (e.g., where, when). They are crucial for crafting fluent, descriptive, and complex sentences, helping you avoid overly simplistic statements and demonstrate a wider grammatical range in your IELTS writing.
Examples
  1. 1
    The report which was published yesterday highlights environmental concerns relevant to many IELTS Task 2 topics.
  2. 2
    The chart displays data for several countries, where significant variations can be observed.

1 Defining Relative Clauses

Defining relative clauses provide essential information to identify the specific noun (person or thing) we are discussing; the sentence's core meaning is often unclear without them. They are not separated by commas from the main clause. You can often use that instead of who (for people) or which (for things).
Examples
  1. 1
    The graph that illustrates unemployment rates shows a downward trend. (Specifies which graph)
  2. 2
    Policies which aim to reduce carbon emissions are crucial for environmental protection. (Identifies which policies)
  3. 3
    The solutions that were proposed by the committee are now under consideration.

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence uses a defining relative clause correctly?
  2. 2 In which sentence does the relative clause provide essential identifying information?
  3. 3 Combine these sentences using a defining relative clause: 'The graph shows unemployment rates. The graph illustrates a downward trend.' Start with 'The graph'.
  4. 4 Transform this into a defining relative clause: 'Policies aim to reduce carbon emissions. These policies are crucial for environmental protection.' Begin with 'Policies'.

2 Non-Defining Relative Clauses

Non-defining relative clauses offer additional, non-essential information about a noun whose identity is already clear (e.g., a unique item or a previously specified noun). They are always separated from the main clause by commas, and you cannot use that as the relative pronoun. These clauses enrich your writing, adding descriptive detail useful for IELTS Task 1 introductions or Task 2 supporting points.
Examples
  1. 1
    The city's population, which has grown rapidly in recent years, faces significant infrastructure challenges.
  2. 2
    Professor Davies, who is a leading expert on sustainable agriculture, presented compelling data.
  3. 3
    The Kyoto Protocol, which was adopted in 1997, aimed to reduce greenhouse gas emissions.

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence correctly uses a non-defining relative clause?
  2. 2 Which relative pronoun cannot be used in non-defining relative clauses?
  3. 3 Add a non-defining relative clause to this sentence: 'Professor Davies presented compelling data.' The clause should be 'who is a leading expert on sustainable agriculture'. Provide the complete sentence.
  4. 4 Convert this into a sentence with a non-defining relative clause: 'The Kyoto Protocol was adopted in 1997. The Kyoto Protocol aimed to reduce greenhouse gas emissions.' Start with 'The Kyoto Protocol'.

3 Key Differences: Defining vs. Non-Defining

Defining clauses identify a noun and do not use commas; 'that' is often permissible as the relative pronoun. Non-defining clauses add extra, non-essential details about an already clear noun, always use commas to separate them from the main clause, and cannot use 'that'. This distinction is crucial for sentence clarity and correct punctuation in formal IELTS writing.
Examples
  1. 1
    Defining: The study that focused on urban development revealed interesting trends. (Identifies *which* study)
  2. 2
    Non-Defining: The recent study by Oxford University, which focused on urban development, revealed interesting trends. (The study is already identified; the clause adds extra info)
  3. 3
    Defining: The data that shows a decline is from 2020.
  4. 4
    Non-Defining: The latest official data, which shows a decline, is from 2020.

Practice: 4 questions

Answer first, then check.

  1. 1 Which pair correctly demonstrates the difference between defining and non-defining relative clauses?
  2. 2 When is a relative clause considered defining rather than non-defining?
  3. 3 Transform this defining example into a non-defining one: 'The data that shows a decline is from 2020.' Change it to refer to 'The latest official data' and make it non-defining.
  4. 4 Convert this non-defining clause into a defining one: 'The recent study by Oxford University, which focused on urban development, revealed interesting trends.' Make it simply identify 'which study'.

4 Relative Pronoun: Who/Whom

Who refers to people and typically acts as the subject of the relative clause. Whom (more formal) refers to people as the object of the verb or a preposition in the relative clause. For IELTS writing, correctly using who is essential. In highly formal writing, such as academic papers, whom is the correct object form. While using who as an object is common in general English, being able to use whom correctly can add a layer of formality appreciated in IELTS.
Examples
  1. 1
    The researchers who conducted the survey analyzed responses from 1,000 participants. (Who is subject)
  2. 2
    The expert panel, whom the government consulted, recommended several policy changes. (Formal object of verb 'consulted')
  3. 3
    The individuals to whom the letter was addressed were senior managers. (Formal object of preposition 'to')
  4. 4
    The individuals who were interviewed expressed diverse opinions on the matter.

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence correctly uses 'whom' in formal writing?
  2. 2 In which sentence is 'who' correctly used as the subject of the relative clause?
  3. 3 Complete this sentence using the formal object form: 'The individuals __ the letter was addressed were senior managers.' Use the appropriate relative pronoun with preposition.
  4. 4 Transform this using 'whom' correctly: 'The government consulted the expert panel. The expert panel recommended several policy changes.' Begin with 'The expert panel'.

5 Relative Pronoun: Which

Which refers to animals and things in both defining and non-defining clauses; remember to use commas for non-defining ones. Crucially for IELTS, which can also refer to a whole clause or idea (the entire preceding statement), providing a sophisticated way to comment or add further information. This usage is always non-defining and requires a comma before it.
Examples
  1. 1
    The policy which the government introduced last year has had mixed results. (Defining)
  2. 2
    The company's annual report, which was released yesterday, showed strong growth. (Non-defining)
  3. 3
    Many factories continue to emit pollutants into the atmosphere, which contributes significantly to acid rain. (Refers to the whole preceding clause)

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence correctly uses 'which' to refer to an entire preceding clause?
  2. 2 Which sentence uses 'which' in a defining relative clause correctly?
  3. 3 Complete this sentence using 'which' to refer to the entire preceding clause: 'Many students fail to prepare adequately for exams, __ often leads to disappointing results.'
  4. 4 Transform this into a non-defining relative clause: 'The company's annual report was released yesterday. The company's annual report showed strong growth.' Start with 'The company's annual report'.

6 Relative Pronoun: That

That can refer to people, animals, and things, but only in defining relative clauses. It is common and can make writing sound natural. However, it's crucial not to use that in non-defining clauses (those requiring commas). For academic writing, especially when referring to people, 'who' is often preferred over 'that' in defining clauses for a more formal tone, but 'that' is not incorrect.
Examples
  1. 1
    The information that is presented in the first graph is particularly noteworthy.
  2. 2
    The government implemented measures that were designed to boost the economy.
  3. 3
    The new policy, that was controversial, faced opposition. (Incorrect: should be 'which' because it's non-defining)

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence incorrectly uses 'that' in a relative clause?
  2. 2 When is it appropriate to use 'that' instead of 'who' or 'which'?
  3. 3 Rewrite this sentence replacing 'which' with 'that': 'The information which is presented in the first graph is particularly noteworthy.'
  4. 4 Correct this sentence by replacing 'that' with the appropriate relative pronoun: 'The new environmental policy, that was introduced last month, has been widely criticized.'

7 Omitting Relative Pronouns

In defining relative clauses, you can often omit the relative pronoun (who, whom, which, that) if it is the object of the verb in the clause. This makes sentences more concise. You cannot omit the pronoun if it is the subject of the clause, nor can you omit it in non-defining clauses. This is a useful technique for varied sentence structure in IELTS.
Examples
  1. 1
    The data (that/which) the report presents is from reliable sources. (Can be: The data the report presents...)
  2. 2
    The expert (who/whom) they consulted advised caution. (Can be: The expert they consulted...)
  3. 3
    The factor that causes this phenomenon is still debated. (Subject, cannot be omitted)

Practice: 4 questions

Answer first, then check.

  1. 1 In which sentence can the relative pronoun be omitted?
  2. 2 Which version correctly omits the relative pronoun?
  3. 3 Rewrite this sentence omitting the relative pronoun: 'The expert whom they consulted advised caution.'
  4. 4 Remove the relative pronoun from this sentence: 'The data which the report presents is from reliable sources.'

8 Advanced Skill: Using Reduced Relative Clauses

For more concise and sophisticated sentences, especially in formal academic writing, you can often reduce relative clauses. This involves using a participle (-ing form for active voice, -ed/-en form for passive voice) instead of the relative pronoun and the verb 'to be' or a full verb phrase. This is particularly common with defining relative clauses.
Examples
  1. 1
    Original: The report which was published yesterday outlined new strategies. / Reduced: The report published yesterday outlined new strategies.
  2. 2
    Original: The scientists who are researching this topic have made a breakthrough. / Reduced: The scientists researching this topic have made a breakthrough.
  3. 3
    Original: The solutions that were proposed by the council faced opposition. / Reduced: The solutions proposed by the council faced opposition.
  4. 4
    Any student wishing to apply must submit their form by Friday. (from 'Any student who wishes to apply...')

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence correctly uses a reduced relative clause?
  2. 2 Which is the correct reduced form of 'The scientists who are researching this topic have made a breakthrough'?
  3. 3 Reduce this relative clause: 'The solutions that were proposed by the council faced opposition.' Start with 'The solutions'.
  4. 4 Convert this to a reduced relative clause: 'Any student who wishes to apply must submit their form by Friday.' Begin with 'Any student'.

9 Using Quantifiers like 'some of whom/which'

For sophisticated sentence structures in IELTS writing, use quantifiers (e.g., some, many, most, none, several, both, all, half, a few) with of whom (for people) or of which (for things). This structure is typically used in non-defining clauses (set off by commas) and adds precise detail, excellent for summarizing data or adding nuanced information.
Examples
  1. 1
    The survey involved 500 participants, most of whom were university students.
  2. 2
    The report highlighted several key issues, some of which require urgent attention from policymakers.
  3. 3
    The development projects, all of which were funded by international aid, transformed the region.

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence correctly uses a quantifier with a relative pronoun?
  2. 2 Which quantifier structure is appropriate for referring to things?
  3. 3 Complete this sentence using 'some of which': 'The report highlighted several key issues, __ require urgent attention from policymakers.'
  4. 4 Combine these using 'all of which': 'The development projects were funded by international aid. The development projects transformed the region.' Start with 'The development projects'.

10 Placement and Clarity

Always place relative clauses as close as possible to the noun (or noun phrase) they describe. This ensures clarity and avoids ambiguity in your IELTS writing. Misplaced clauses can confuse the reader by making it unclear which noun is being modified, which is vital for coherent arguments and descriptions.
Examples
  1. 1
    Correct: The graph that illustrates population growth is on page five. (Clear: 'that illustrates population growth' modifies 'The graph')
  2. 2
    Potentially Unclear: The graph is on page five that illustrates population growth. (Could ambiguously imply 'page five' illustrates population growth)
  3. 3
    Correct: The report on climate change, which was commissioned by the UN, outlines several risks.

Practice: 4 questions

Answer first, then check.

  1. 1 Which sentence places the relative clause correctly for clarity?
  2. 2 Why should relative clauses be placed close to the noun they modify?
  3. 3 Rewrite this sentence to place the relative clause correctly: 'The graph is on page five that illustrates population growth.'
  4. 4 Improve the clarity of this sentence by repositioning the relative clause: 'The report was commissioned by the UN on climate change which outlines several risks.'

11 Relative Clauses: IELTS Advantage

Using relative clauses effectively significantly boosts your 'Grammatical Range and Accuracy' score in IELTS. They enable complex sentence construction, vital for nuanced Task 1 data descriptions and sophisticated Task 2 arguments. This skill demonstrates advanced English proficiency, adding precision, fluency, and a formal academic style to your writing. Mastering them is a key step towards achieving a higher band score.
Examples
  1. 1
    Task 1 Data: The chart presents data on renewable energy sources, the most prominent of which has been solar power in recent years.
  2. 2
    Task 1 Process: Once the components are manufactured, they are sent to an assembly line, where they are put together by skilled workers.
  3. 3
    Task 2 Argument (Defining): Students who participate in extracurricular activities often develop better teamwork skills.
  4. 4
    Task 2 Argument (Non-Defining): Global warming, which poses a threat to ecosystems worldwide, requires concerted international effort.
  5. 5
    Task 2 Adding Detail: The increasing use of technology in education, which has become a prominent trend recently, offers numerous benefits for learners.
  6. 6
    Task 2 Precision: The government introduced new legislation that aims to protect endangered species.

Lesson summary

The 10 points to remember from this lesson.

  1. 1
    Relative clauses add essential or extra information about a noun, improving sentence complexity.
    Example: The scientist who made the discovery became famous.
  2. 2
    Defining relative clauses identify the noun and do not use commas; 'that' can often be used.
    Example: The book that I borrowed is fascinating.
  3. 3
    Non-defining relative clauses provide extra information about an already identified noun and are set off by commas; 'that' cannot be used.
    Example: The Eiffel Tower, which is in Paris, is a famous landmark.
  4. 4
    Use 'who' for people (subject) and 'whom' (formal) for people as objects in relative clauses.
    Example: The manager whom they hired has extensive experience.
  5. 5
    'Which' is used for things/animals and can refer to an entire preceding clause (always non-defining with a comma).
    Example: He passed his exam, which was a great relief to his parents.
  6. 6
    'That' is used in defining clauses for people or things, but avoid it in non-defining clauses.
    Example: The strategy that the company adopted proved successful.
  7. 7
    Omit the relative pronoun (who, which, that) in defining clauses if it's the object of the verb.
    Example: The subject (which) we discussed was complex. -> The subject we discussed was complex.
  8. 8
    Reduced relative clauses use participles (-ing/-ed) for conciseness, replacing the pronoun and verb.
    Example: The results published in the journal were groundbreaking. (from '...which were published...')
  9. 9
    Use quantifiers like 'many of whom' or 'several of which' in non-defining clauses for precise detail.
    Example: The attendees, several of whom were international delegates, engaged in lively discussions.
  10. 10
    Always place relative clauses immediately after the noun they modify to ensure clarity.
    Example: The diagram showing the process is on the next page.

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