What are the 12 types of relative clause in English?

This is the second of three chapters about Relative Clauses. To complete this reader, read each chapter carefully and then unlock and complete our materials to check your understanding.   

– Review the major features of relative clauses in English

– Discuss the six categories and twelve types of relative clause

– Study examples of each type to help with identification

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Chapter 2

In this second chapter on relative clauses, we review the key aspects of this grammatical structure and introduce its twelve key types, dividing them into six categories. Because relative clauses are so common in both written and spoken English, and because these structures help students make their essay writing more concise, it may be a good idea to study this grammar topic carefully if you wish to improve your grades at university.

Review Relative Clauses

Before studying relative clauses, it’s important that we first review the key aspects of this structure as discussed in Chapter 1. Relative clauses:


  • are a type of dependent clause
  • are also known as adjective clauses
  • usually contain a minimum of a subject and a verb
  • directly follow the noun or noun phrase they modify
  • define, identify or provide extra information about a person or thing
  • are usually introduced by relative pronouns (and sometimes by adverbs)
  • can be divided into twelve types among six distinct categories


Category 1: Bound Relative Clauses

Bound relative clauses, which are those clauses which are bound to (connected with) a preceding element, are by far the most common category. As the following table shows, such relative clauses in English may be bound to subject or object phrases which they define, identify or add extra information about:

If you need some extra help with recognising direct, indirect and oblique objects, visit our short course on subject and object phrase functions.


Category 2: Free Relative Clauses

Unlike their bound counterparts, free relative clauses are not bound to preceding phrase elements like subjects and objects. As the below demonstrates for example, the clause ‘what you submitted’ does not describe or identify anything in the preceding clause ‘I graded’ but is simply the object of the verb ‘grade’.

While much less common than bound relative clauses, this category is unique because the word ‘what’ can be used as a relative pronoun. English speakers are in fact recommended to use ‘who/whom/whoever/whomever’ when forming free relative clauses about people and ‘what/whatever/whichever’ for those about things.

Category 3: Restrictive Relative Clauses

Restrictive (also known as defining) relative clauses are very common in English and are formed from the six bound types mentioned in Category 1. What makes a relative clause restrictive/defining is that the information that clause provides is necessary to correctly understand or identify the preceding noun. If we remove the relative clause ‘who studies hard’ in the following sentence, for example, the meaning of the expression changes. With the clause, the meaning is ‘only diligent students will succeed’, whereas without that clause ‘any student is able to succeed’:

Category 4: Non-Restrictive Relative Clauses

Non-restrictive (or non-defining) relative clauses, on the other hand, provide additional information. While the relative clause ‘which you may find difficult’ might be important or interesting, it is not necessary for defining or identifying the preceding noun phrase ‘the final exam’:

In spoken English, we usually pause when introducing non-restrictive relative clauses, whereas in the written word we use bracketing commas (,). Note also that while restrictive relative clauses can only modify nouns and noun phrases, the non-restrictive type may provide extra information about an entire expression, such as in the sentence ‘He’s always late and never does his homework, which I don’t like’.


Category 5: Reduced Relative Clauses

The fifth category, the reduced relative clause, can be problematic for students. This is because the normal indicators of a relative clause are not present. While relative pronouns such as ‘who’ and ‘which’ are usually used to introduce relative clauses, this is not true when the clause is reduced:

In (5a), the relative clause ‘studying for the exam’ has been reduced from the expression ‘who study for the exam’, while in (5b) the clause ‘my teacher created’ is missing its relative pronoun ‘that/which’. When forming reduced relative clause, there are three rules to remember:


  1. i) Object relative pronouns can be deleted for restrictive relative clauses only.
  2. ii) When deleting subject relative pronouns for restrictive relative clauses, the present participle form of the verb (i.e., ‘studying’) should be used.
  3. iii) When deleting subject relative pronouns with non-restrictive relative clauses, this is only possible with pronouns that precede a ‘be’ verb; both the pronoun and the ‘be’ verb should be removed.

Category 6: Infinitival Relative Clauses

The final category, the infinitival relative clause, is probably the least recognisable in English as being a relative clause, but they are more common than you might think. These clauses use infinitive verbs with ‘to’ or present-participle verbs using ‘-ing’:

Category 5’s reduced relative clauses that use present participles such as ‘studying for the exam’ are therefore (once reduced) also types of infinitival relative clause.

Great work on finishing Chapter 2. Now you’re familiar with the six categories and twelve types of relative clause in English, let’s study the eight grammar rules that make for perfectly formed clauses – and therefore higher grades.

2 of 3 Chapters Completed


Once you’ve completed all three chapters in this short reader about Relative Clauses, you might then wish to download our Chapter Worksheets to check your progress or print for your students. These professional PDF worksheets can be easily accessed for only a few Academic Marks.

Chapter 1 explores the topic: What are relative clauses and are they important? Our Chapter 1 Worksheet (containing guidance, activities and answer keys) can be accessed here at the click of a button. 

Chapter 2 explores the topic: What are the 12 types of relative clause in English? Our Chapter 2 Worksheet (containing guidance, activities and answer keys) can be accessed here at the click of a button. 

Chapter 3 explores the topic: Which 8 rules make relative clauses grammatical? Our Chapter 3 Worksheet (containing guidance, activities and answer keys) can be accessed here at the click of a button. 

To save yourself 2 Marks, click on the button below to gain unlimited access to all of our Relative Clauses Chapter Worksheets. This All-in-1 Pack includes every chapter, activity and answer key related this topic in one handy and professional PDF.

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