An adjective clause is a clause that works to describe (modify) a noun or pronoun. It will always be a subordinate clause. It appears immediately after the word it describes (modifies).
Adjective clauses always begin with either a pronoun or an adverb.
Adjective clauses answer questions that begin with which, who, when, or what kind.
Example 1:
“I do feel so sorry,” said Draco Malfoy, one Potions class, “for all those people who have to stay at Hogwarts for Christmas because they’re not wanted at home.”
-J.K Rowling, Harry Potter and the Philosopher’s Stone
In this example, the adjective clause is describing the noun ‘people’. It is giving the reader more information about the kind of people that Draco feels sorry for. It begins with the pronoun ‘who’, and answers the question, “Which people?”
Example 2:
“Those who cannot remember the past are condemned to repeat it.”
Here, the adjective clause is describing the pronoun ‘those’ – it is giving us more information on who those people are. It begins with the pronoun ‘who’, and ‘who is the subject of the clause.
Example 3:
The four gas giant planets, which are Jupiter, Saturn, Neptune, and Uranus, are further away from the Sun than the rocky planets.
The adjective clause in this sentence is describing the gas giant planets in more detail. It is giving the reader more description about the outer planets. The clause begins with the pronoun ‘which’ and answers the question, “Which planets?”
Example 4:
The time when fish are easiest to catch is at dawn.
This adjective clause is our first example of one starting with an adverb. It begins with the adverb ‘when’. Note that ‘when’ is not the subject of the adjective clause – ‘fish’ is.
An adjective clause must have the two parts that every clause has: a subject (what the clause is about) and a verb (what the subject is doing). The subject of an adjective clause depends on whether it begins with a pronoun or an adverb .
When an adjective clause begins with a pronoun , the pronoun is the subject of the clause.
Example 1:
The man who owns Curious George wears a yellow hat.
In this example, ‘ who ’ is a pronoun and the subject of the adjective clause. The clause describes ‘man’, which is the subject of the main clause ‘The man wears a yellow hat.’ ‘Owns’ is the verb, because it is the action that ‘ who ’ is doing.
Example 2:
The dog that performs the most tricks will win the prize.
The subject of this adjective clause is ‘ that ’, and the clause modifies the word ‘dog’. The verb here is ‘performs’ because that is what the subject, ‘ that ’, is doing.
When an adjective clause begins with an adverb , the noun or pronoun following the adverb is the subject.
Example 1:
The restaurant where they serve fried zucchini is my favorite.
This adjective clause begins with an adverb (‘ where ’). The subject of the clause is the pronoun ‘ they ’. The verb is ‘serve’, and the adjective clause describes the restaurant.
Example 2:
Do remember that time when we saw an eagle flying?
The adverb ‘ when ’ begins this adjective clause. The subject of the clause is ‘ we ’, the verb is ‘saw’, and the adjective clause describes ‘time’. The clause answers the question, “Which time?”
There are two kinds of adjective clauses: restrictive and non-restrictive.
a. A restrictive clause is one that limits or restricts the noun or pronoun it modifies. It makes the noun or pronoun more specific. Restrictive clauses have information that is essential to the meaning of the sentence.
Example 1
People who are rude are difficult to be around.
This adjective clause is restrictive. It limits the type of person that the subject ‘people’ is about. The sentence is not about all people, but about a limited group of people: ones who are rude. If this adjective clause were removed, the meaning of this sentence would be very different.
Example 2
The button that is on top turns on the machine.
This adjective clause is restrictive. It limits the noun ‘button’ – it lets the reader know which button is being identified. This would be useful if there were several buttons, and the reader wanted to know which one to use. If this clause were removed, the reader would not know how to turn the machine on.
b. A non-restrictive clause does not limit the noun or pronoun it modifies; instead, it gives a bit of additional information. Non-restrictive clauses are not essential to a sentence’s meaning, but add a bit of extra detail.
Example 1
My brother, who is sometimes rude to guests, lives down the street from me.
This adjective clause is non-restrictive. It is adding extra information about ‘my brother’. If this adjective clause were removed, the main message of the sentence would remain the same.
Example 2:
The button, which is green, is at the top of the row.
The adjective clause here is non-restrictive – it does not limit the ‘button’ in any way. Instead, it is adding a little bit of extra information. If this clause were removed, the reader would still know which button the sentence refers to.
Remember, an adjective clause is a subordinate (dependent) clause. It cannot be the only clause in a sentence; it needs to be attached to an independent clause.
Example 1
The farm where we can pick our own strawberries is so much fun!
This sentence is correct. The adjective clause is describing the farm, and is connected to the independent clause ‘The farm is so much fun!’ Note that this is an example of a restrictive clause because it narrows down (limits) which farm is being mentioned.
Where we can pick our own strawberries.
This is an incorrect use of an adjective clause. It leaves us wondering what place ‘where’ is referring to. There is no independent clause, and so we are left with an incomplete sentence.
Example 2
Italian, French, and Spanish, which are all Romance languages, all come from Latin.
This is a correct usage of an adjective clause. It describes (modifies) the first three languages mentioned. Note that this is an example of a non-restrictive clause. It is giving us additional information; if it were removed, we would still get the main idea of the sentence: Italian, French and Spanish all come from Latin.
Which are all Romance languages.
This adjective clause is used incorrectly. We do not know what the pronoun ‘which’ refers to, and we are left with an incomplete sentence that would make us scratch our heads in confusion.