Relative clauses are useful when you want to give more information about a noun without starting a new sentence. They help combine ideas and make writing more precise.
A relative clause is a type of dependent clause that describes or identifies a noun or pronoun in the main clause. It starts with a relative pronoun like who, which, or that, and it always includes a subject and a verb.
In this article, you’ll learn what relative clauses are, how they work, and how to use them correctly in your writing, with clear examples and explanations.
What Is a Relative Clause?
A relative clause is a group of words that contains a subject and a verb and functions like an adjective. It gives more information about a noun or pronoun in the sentence, often identifying, describing, or adding detail.
Relative clauses always begin with a relative pronoun such as who, whom, whose, which, or that. These pronouns connect the clause to the noun they modify and help form a complete, more informative sentence.
Because relative clauses are dependent clauses, they cannot stand alone. They need to be attached to an independent clause to form a complete thought.
Relative Clause Examples:
- The student who asked the question stayed after class.
(Relative clause = who asked the question, modifying student) - I bought the shoes that were on sale.
(Relative clause = that were on sale, modifying shoes) - She lives in the house which has a red door.
(Relative clause = which has a red door, modifying house)
Relative clauses help reduce repetition and combine sentences smoothly. They’re especially common in formal, academic, and descriptive writing.
Identifying Relative Clauses
To spot a relative clause, look for a group of words that:
- Starts with a relative pronoun such as who, whom, whose, which, or that
- Contains both a subject and a verb
- Directly modifies a noun or pronoun by adding detail or identifying information
Relative clauses often appear right after the noun they describe. They can give essential information (defining) or extra detail (non-defining), depending on how they are used and punctuated.
Common Relative Pronouns:
- Who – for people (as subject)
- Whom – for people (as object)
- Whose – to show possession
- Which – for things
- That – for people or things (in defining clauses)
Examples:
- The musician who won the award thanked her team.
(Who won the award modifies musician) - They adopted a puppy that needed a home.
(That needed a home describes puppy) - The car, which was parked illegally, was towed.
(Which was parked illegally gives extra detail about the car)
Ask yourself: Does this clause describe or identify a noun? If yes—and it starts with a relative pronoun and includes a verb—it’s a relative clause.
Types of Relative Clauses
Relative clauses fall into two categories: defining and non-defining. The difference between them affects both the meaning and punctuation of the sentence.
Defining (Restrictive) Relative Clauses
A defining relative clause gives information that is essential to identify the noun it follows. Without it, the meaning of the sentence would be incomplete or unclear. These clauses are not separated by commas.
Examples:
- Students who submit their work early receive extra feedback.
(This tells us which students are being referred to) - The book that changed my perspective is on the shelf.
(The clause specifies which book)
Non-Defining (Non-Restrictive) Relative Clauses
A non-defining relative clause adds extra detail about a noun that’s already clearly identified. These clauses are set off by commas and are not essential to the core meaning of the sentence.
Examples:
- Mr. Patel, who teaches physics, just won an award.
(The clause adds information, but we already know who Mr. Patel is) - Their house, which overlooks the lake, was built in 1955.
(The clause gives extra detail about their house)
Punctuation Rules for Relative Clauses
How you punctuate a relative clause depends on whether it’s defining or non-defining. Using or omitting commas can completely change the meaning of a sentence.
No Commas for Defining Clauses
Defining relative clauses are essential to the meaning of the sentence. They identify which person or thing you’re referring to, so no commas are used.
Examples:
- The employee who processed your request is on leave.
- The jacket that has a torn sleeve needs to be repaired.
Without these clauses, the noun would be unclear or too general.
Use Commas for Non-Defining Clauses
Non-defining relative clauses add extra information. The noun is already clear without the clause, so commas are needed to set it apart.
Examples:
- My neighbor, who just returned from Spain, brought souvenirs.
- This book, which I read last year, is now out of print.
Removing the clause won’t affect the basic meaning of the sentence.
Common Mistake
❌ The teacher, who assigned the project, is absent.
✔ The teacher who assigned the project is absent.
(Unless you have only one teacher, this clause should be restrictive and written without commas)
Relative Clause vs. Adjective Clause
Many learners wonder if there’s a difference between a relative clause and an adjective clause. In English grammar, the two terms actually refer to the same type of clause.
A relative clause is called that because it begins with a relative pronoun such as who, which, or that. It’s also called an adjective clause because it functions like an adjective—it modifies a noun or pronoun.
So, when someone says “relative clause,” they’re highlighting the word that introduces it. When they say “adjective clause,” they’re focusing on its function in the sentence. Both terms are correct and interchangeable.
Example:
The dog that barked all night kept the neighbors awake.
(That barked all night is both a relative clause and an adjective clause—it modifies dog and starts with a relative pronoun.)
Whether you call it a relative clause or an adjective clause, the structure and purpose are the same: to give more information about a noun.
Frequently Asked Questions About Relative Clauses
What is a relative clause in English grammar?
A relative clause is a group of words that contains a subject and a verb and describes or identifies a noun or pronoun in the main sentence. It starts with a relative pronoun like who, which, or that, and helps combine information into one sentence.
What is the difference between defining and non-defining relative clauses?
A defining relative clause gives essential information about the noun and is not set off by commas. A non-defining clause adds extra detail and is placed between commas. The choice affects both meaning and punctuation.
Can you start a sentence with a relative clause?
No, a relative clause cannot stand alone or begin a sentence by itself. It’s a dependent clause that must be attached to an independent clause that contains the noun it modifies.
What’s the difference between a relative clause and a noun clause?
A relative clause describes a noun and functions like an adjective. A noun clause acts as a noun in the sentence, serving as a subject, object, or complement. Their roles and sentence positions are different.
Is it okay to leave out the relative pronoun?
Sometimes. In defining relative clauses where the relative pronoun is the object, it can often be left out in informal English. For example: The book [that] I borrowed was excellent.