7.4 GRAMMAR: Using Adjective Clauses

Like noun clauses, adjective clauses are also very important to academic writing. Why? Because they offer more precise description, and that makes your writing more interesting and more useful for your readers. Adjective clauses help you add important supporting details in new and different ways.

A CLOSER LOOK

A clause is a group of words with a subject and a verb.

A clause can be independent. That means it has a subject and a verb, and it expresses a complete idea. A simple sentence is an independent clause.

A clause can be dependent. That means it has a subject and a verb, but it does not express a complete idea. It must be attached to an independent clause to make sense.

An adjective clause is a dependent clause. It works like an adjective. It has a subject and a verb, but it does not express a complete idea. An adjective clause almost always comes immediately after the noun that it describes.

Adjective clauses begin with a relative pronoun.

Types of adjective clauses

Here are some examples of relative pronouns and how they are used:

NOTE: In adjective clauses that use who, that, and which as a subject, the verb of the adjective clause agrees with the noun that the adjective clause describes.

Restrictive and non-restrictive adjective clauses

Adjective clauses that do not provide essential information are separated from the rest of the sentence by commas. Adjective clauses that provide essential information are not separated from the rest of the sentence by commas. Compare these two examples:

• René Magritte was a Belgian surrealist artist  who became well known for a number of witty and thought-provoking images.
• René Magritte,  who became well known for a number of witty and thought-provoking images, was a Belgian surrealist artist. 

In the first sentence above, the adjective clause who became well known for a number of witty and thought-provoking images is necessary information. It is important to the author/speaker that you know all of this information about the artist.

In the second sentence above, however, the important part is only that Magritte was a Belgian surrealist artist. The other information is extra and not necessary to understand the meaning of the sentence or the intentions of the author/speaker.

NOTE: We do not use the relative pronoun that in non-restrictive clauses.

Watch this video to learn more:

Using adjective clauses to combine sentences – Part 1

Often you can use an adjective clause to combine sentences. You do this to make your writing more interesting and more precise. To do this, you must:

1. Remove a noun (or noun phrase) from one of the sentences.
2. Replace it with a relative pronoun: who, which, that, whom, where, when, whose + noun.
3. Make sure the relative pronoun is at the front of the adjective clause.
4. Insert the adjective clause into the other sentence, placing it directly after the noun it is describing.

For example:

• The orange cat belongs to my neighbor.
• The orange cat is pregnant.

1. Take out the orange cat  from the second sentence
2. Replace it with a relative pronoun: which
3. Make sure the relative pronoun is at the front of the adjective clause
4. Insert the adjective clause into the other sentence, placing it directly after the noun it is describing.

• The orange cat, which is pregnant, belongs to my neighbor. (“belongs to my neighbor” is the focus)
• The orange cat, which belongs to my neighbor, is pregnant.  (“is pregnant” is the focus)

Now practice with this exercise; it is not graded, and you may repeat it as many times as you wish:

Using adjective clauses to combine sentences – Part 2

This process gets a little confusing when the noun you are working with is a subject in the first sentence but an object in the second. You can still turn the second sentence into an adjective clause by following the same rules. Remember, in formal academic writing, you will usually use whom for people. In this case, when the pronoun is replacing an object, you may omit the relative pronoun from the clause. For example:

• My sister’s favorite necklace is a diamond and silver chain.
• I gave the necklace to her.

1. Take out a noun (or noun phrase) from one of the sentences: I gave __________________ to her
2. Replace it with a relative pronoun: I gave which to her.
3. Make sure the relative pronoun is at the front of the adjective clause: which I gave to her.
4. Insert the adjective clause into the other sentence, placing it directly after the noun it is describing.

• My sister’s favorite necklace, which I gave to her, is a diamond and silver chain.

Practice

Now practice with this exercise; it is not graded, and you may repeat it as many times as you wish:

Reducing adjective clauses

Sometimes we can make adjective clauses shorter.  When the relative pronoun functions as an object of the adjective clause, we often omit the relative pronoun. For example:

• Many people who I know enjoy visiting museums to look at art.
• Many people that I know enjoy visiting museums to look at art.
• Many people I know enjoy visiting museums to look at art. (informal)

When the relative pronoun functions as the subject of the adjective clause, it can sometimes be reduced to a phrase. There are two rules:

First, if the adjective clause contains the be verb, then omit the relative pronoun and the be verb:

• Students who are skilled in critical thinking will be successful in school.
• Students skilled in critical thinking will be successful in school.

Second, we can sometimes reduce adjective clauses that do not have the be verb. Here, omit the relative pronoun and change the verb to the -ing (present participle) form:

• Students who study in college should know about critical thinking.
• Students studying in college should know about critical thinking.

Practice

Now practice with this exercise; it is not graded, and you may repeat it as many times as you wish:

Optional: Where to get more information

If you want more instruction and examples about adjective clauses, try these links:

• SmrtEnglish Video: Adjective Clauses
• Relative Clause Practice Quiz
• UVic: Adjective Clauses

Video from: Benn, Adam. “Learn English Grammar: The Adjective Clause (Relative Clause).” YouTube, 15 Nov. 2016, www.youtube.com/watch?v=GpV39YEmh5k. Accessed 27 Aug. 2021.