An adjective clause is a type of dependent clause that modifies a noun or pronoun. It begins with a relative pronoun or relative adverb and includes a subject and a verb. Although it cannot stand alone, it gives important or helpful information about the noun it follows.
In this guide, you’ll learn what adjective clauses are, how they work, and how to use them correctly with examples you can apply in real writing.
What Is an Adjective Clause?
An adjective clause, also known as a relative clause, is a group of words that contains a subject and a verb and describes a noun or pronoun in the sentence. It answers questions like which one?, what kind?, or who? and helps provide more detail about the noun it follows.
Because it’s a type of dependent clause, an adjective clause cannot stand alone. It depends on the main sentence for meaning and always modifies a noun directly before it.
Here are two examples:
- The student who asked the question stayed after class.
(Who asked the question describes the student) - I found the keys that you lost yesterday.
(That you lost yesterday tells us which keys)
Adjective clauses usually begin with words like who, whom, whose, which, that, or adverbs like where, when, or why. These words connect the clause to the noun it describes.
Identifying Adjective Clauses
To recognize an adjective clause, look for a group of words that begins with a relative pronoun or relative adverb and provides more information about a noun or pronoun in the sentence. The clause must contain a subject and a verb, and will always function as a modifier.
Common Introductory Words
Adjective clauses often begin with:
- Relative pronouns: who, whom, whose, which, that
- Relative adverbs: where, when, why
These words link the clause to the noun it describes.
Example 1:
The athlete who broke the record trained for months.
Here, who broke the record is an adjective clause modifying the athlete. It tells us which athlete the sentence is about.
Example 2:
She visited the bakery where they sell fresh sourdough every morning.
The clause where they sell fresh sourdough every morning gives more details about the bakery.
Example 3:
I saw the painting that everyone was talking about.
The clause that everyone was talking about tells us which painting is being referred to.
How to Spot It
Ask yourself:
- Does this group of words describe a noun or a pronoun?
- Does it start with a relative word and include a subject and a verb?
If the answer is yes to both, it’s an adjective clause.
Types of Adjective Clauses
Adjective clauses are grouped into two main types based on whether the information they provide is essential to the meaning of the sentence. These types are known as restrictive clauses and non-restrictive clauses.
Restrictive (Essential) Clauses
A restrictive clause gives information that is necessary to identify the noun it modifies. Without it, the sentence would lose important meaning. These clauses are not separated by commas.
Example 1:
The employee who processed your request is on leave today.
This clause tells us which employee is being referred to—it’s essential to the meaning.
Example 2:
Books that include practical examples are easier to understand.
We’re not talking about all books—only the ones with practical examples.
Non-Restrictive (Non-Essential) Clauses
A non-restrictive clause adds extra information that is not required to understand the noun. These clauses are set off by commas because the sentence would still be complete without them.
Example 1:
My cousin, who lives in Boston, just started a new job.
Here, the clause gives additional detail, but we already know who my cousin is.
Example 2:
The Eiffel Tower, which attracts millions of visitors every year, was built in 1889.
Even without the clause, the meaning of The Eiffel Tower was built in 1889 is still clear.
Quick Reminder:
- No commas = restrictive (essential)
- Commas = non-restrictive (extra detail)
Knowing the difference helps you use punctuation correctly and avoid confusion in longer sentences.
Punctuation Rules for Adjective Clauses
Punctuation can change the meaning of a sentence that includes an adjective clause. Whether or not you use commas depends on the type of adjective clause—restrictive or non-restrictive.
No Commas for Restrictive Clauses
When the adjective clause is essential to identify the noun, do not use commas.
- ✔ Students who submit their work on time will receive feedback.
(Only those students are being referred to—no commas needed) - ✔ The shoes that she wore to the interview were custom-made.
(The clause tells us exactly which shoes)
Adding commas here would make the sentence unclear or suggest a different meaning.
Use Commas for Non-Restrictive Clauses
If the adjective clause simply adds extra information, set it off with commas.
- ✔ Liam, who just joined the team, will handle the presentation.
(The clause adds detail, but we already know who Liam is) - ✔ The museum, which was closed last weekend, reopened today.
(The sentence would still make sense without the clause)
Common Mistake to Avoid
❌ The manager who approved the request, will meet us later.
✔ The manager who approved the request will meet us later.
(No commas—this clause is essential to identify which manager)
Correct punctuation helps make your meaning clear and ensures your writing flows properly.
Adjective Clause vs. Adjective Phrase
Adjective clauses and adjective phrases both describe nouns, but they differ in structure. Understanding the difference helps you recognize how detail is added in different ways.
An adjective clause includes a subject and a verb. It often begins with a relative pronoun such as who, that, or which and functions as a dependent clause. It gives specific, often necessary, information about a noun.
An adjective phrase, on the other hand, is a group of words without a subject-verb combination. It acts like an adjective and typically includes modifiers but no clause structure. Adjective phrases are usually shorter and more flexible in placement.
Examples:
Adjective Clause:
- The team that won the regional championship will advance to the finals.
(that won the regional championship = contains subject and verb)
Adjective Phrase:
- The team winning the regional championship will advance to the finals.
(winning the regional championship = no subject, just a participial phrase)
Both provide detail about the team, but the clause gives a full idea with a subject and verb, while the phrase keeps it brief and focused.
Frequently Asked Questions About Adjective Clauses
What is an adjective clause in English grammar?
An adjective clause is a group of words that contains a subject and a verb and describes a noun or pronoun. It adds more detail by answering questions like which one? or what kind? and usually begins with a relative pronoun like who, which, or that.
How do I know if a clause is an adjective clause?
If the clause starts with a relative word, contains a subject and a verb, and provides extra information about a noun or pronoun nearby, it’s an adjective clause. It will always follow the noun it modifies.
What is the difference between restrictive and non-restrictive adjective clauses?
A restrictive clause provides essential information about the noun and does not use commas. A non-restrictive clause adds extra detail and is set off with commas. The difference affects both meaning and punctuation.
Can I omit the relative pronoun in an adjective clause?
Sometimes. In informal writing or speech, the relative pronoun that is often dropped when it’s the object of the clause. For example: The book [that] I borrowed was excellent.
Do adjective clauses always come after the noun?
Yes, adjective clauses directly follow the noun or pronoun they modify. Placing them elsewhere would confuse the sentence structure and the meaning.