What is an Adjective clause? How to use Adjective clauses in English

Adjective clauses are an advanced grammatical topic in English. In today's article, PREP will analyze in detail to help you understand the definition, usage, formation structure, how to reduce, and differentiate between Adjective clauses and adjective phrases. Read now!

I. What is an Adjective clause?

What is an Adjective clause? An Adjective clause, also known as a relative clause, is a type of dependent clause used to describe or modify a noun, functioning like an adjective. Adjective clauses often begin with a relative pronoun such as "that," "which," or "who".

• Jack caught a fish, which was gigantic! ➞ “which was gigantic” is an Adjective clause, modifying the noun “fish”.
• The guy who lives next to my house is a painter. ➞ “who lives next to my house” is an Adjective clause, modifying the subject “the guy”.

II. Usage & structure of Adjective clauses

Let's explore the usage and formation structure of Adjective clauses in English with PREP!

1. Adjective clauses beginning with relative pronouns

Adjective clauses are often referred to as relative clauses because they typically begin with relative pronouns. For example:

• The new restaurant, which just opened last month, has already closed down. 
• I took my partner, who has never seen snow, on a ski trip.

Some common relative pronouns that appear in Adjective clauses include:

Note:

• In addition, the relative pronouns "Whoever, Whomever, Wherever, Whichever" can also be used as Adjective clauses, but these pronouns are much less common than the ones listed above. For example: We will take either a taxi or bus, whichever comes first. 
• Similarly, the relative pronoun "Why" can sometimes be used for Adjective clauses, although its usage as a relative pronoun is rare. For example: The movie Annabelle is the reason why I got rid of my doll collection. 

2. Adjective clauses require a subject and a verb

The main characteristic of a clause is that it includes a subject and a verb. Adjective clauses are no exception, meaning each clause must have its own subject and verb. For example:

• My coach didn’t believe that I won my first wrestling match. 
• The teacher supposes that Peter will get the first prize. 

Sometimes, the subject of an Adjective clause is a relative pronoun. For example:

• I need a roommate who is not afraid of spiders. 
• I don’t want a boyfriend who is always decrying me. 

3. Adjective clauses need to be combined with independent clauses

Because Adjective clauses are dependent clauses, they need to be combined with an independent clause to form a complete sentence. In other words, an Adjective clause cannot stand alone. For example:

• Where they have Wi-Fi. (❌)
• Let’s go to a cafe where they have Wi-Fi (✅)

4. Adjective clauses must describe a noun in the independent clause

Adjective clauses modify nouns, meaning that they must describe a noun in the main clause. This noun can be the subject, direct object, object of a preposition, or any other role of a noun. For example:

• Maria didn’t wake from the nap until 6 p.m, when the sun was setting. 
• I don’t go home after school until 5p.m, when the bell is ringing. 

5. Adjective clauses come after the noun

Unlike regular adjectives that typically come before the noun they modify, Adjective clauses always come after the noun. For example:

• The rich lady whose house we were at wasn’t even home. 
• The boy whose money that I borrow is very generous. 

Note: Do not start a sentence with an Adjective clause. Instead, we start a sentence with a noun clause or a relative pronoun clause:

• Whoever eats the most hot dogs gets the trophy. ➞ “Whoever eats the most hot dogs” is a noun clause.
• The winner, whoever eats the most hot dogs, gets the trophy. ➞ “Whoever eats the most hot dogs gets” is an Adjective clause.

III. Reduced Adjective clauses 

In a sentence, we can omit the relative pronoun in an Adjective clause while still maintaining the meaning and grammatical correctness of the sentence. For example:

• This is the book that I was talking about. = This is the book I was talking about. 
• This is the movie that I have seen three times. = This is the movie I have seen three times. 

So when should we not omit the relative pronoun? If the relative pronoun functions as the subject in the Adjective clause, you cannot omit it. For example:

• I met someone she dated in high school. (❌)
• I met someone whom she dated in high school (✅)

A tip to remember when you can omit the relative pronoun in an Adjective clause is:

• If the relative pronoun is followed by a verb ➞ we CANNOT omit the relative pronoun.
• If the word following the relative pronoun is a noun ➞ we CAN omit the relative pronoun.

IV. Differentiating between Adjective clauses and adjective phrases

How are Adjective clauses and adjective phrases different? Let's use PREP to distinguish the usage of Adjective clauses and adjective phrases below!

V. Exercise on Adjective clauses

To further reinforce your knowledge of reduced Adjective clauses and how to write sentences containing Adjective clauses, let's complete the exercise below with PREP!

1. Exercises

Exercise 1: Use your understanding of Adjective clauses and rewrite the sentence:

1. The man was sick. He looked very pale.
2. He was sitting in the emergency room. It was very crowded.
3. A nurse was nearby. He called her.
4. The nurse called a doctor. She came quickly.
5. The doctor asked him to lie down. She looked very worried.

Exercise 2: Choose the correct answer:

1. The cougar, ______ grows to around 8 feet in length, is a member of the cat family.
   1. whom
   2. who
   3. which
   4. that
2. Cougars sometimes prey on sheep and goats, so they may be killed by the farmers ________ animals they attack.
   1. which
   2. whom
   3. who
   4. whose
3. The cougar has powerful legs, ________ it uses to climb and to jump into trees.
   1. which
   2. whom
   3. who
   4. whose
4. The cougar lives in deserts, forests, plains and mountains, but according to scientists ________ have studied the animal, it is becoming endangered in some areas.
   1. whom
   2. which
   3. who
   4. whose
5. However, cougars very rarely attack humans, of ________ they are usually afraid.
   1. who
   2. whom
   3. which
   4. that

2. Answer

Exercise 1:

1. The man, who was sick, looked very pale.
2. He was sitting in the emergency room, which was very crowded.
3. He called a nurse, who was nearby.
4. The nurse called a doctor, who came quickly.
5. The doctor, who looked very worried, asked him to lie down.

Exercise 2:

VI. Achieve Your Dream IELTS Band Score 

PREP hopes that through this article, you have grasped the definition, structure, and usage of Adjective clauses in English. If your goal is to achieve a Band 7 or higher, these IELTS resources are for you :

• IELTS preparation course: Score Big in IELTS With Our Expert Tips!