12 Grammar: Adjective Clauses
What do you already know?
Read these sentences:
- Adaku is looking for a book. She saw it yesterday in the library.
- Adaku is looking for a book that she saw yesterday in the library.
What is an adjective clause?
What is an adjective?
An adjective describes a noun or noun phrase.
What is a clause?
A clause is a group of words that contain a subject and a verb. An independent clause is a complete idea; a simple sentence is an example of an independent clause. A dependent clause, however, is not a complete idea.
What is an adjective clause?
An adjective clause is a dependent clause that describes a noun or noun phrase. An adjective clause comes after the noun that it modifies.
Take another look
- My neighbor knows all of the quick and easy ways to get to the airport. He drives for both Uber and Lyft.
- My neighbor, who drives for both Uber and Lyft, knows all of the quick and easy ways to get to the airport.
How do you make an adjective clause?
To combine two separate sentences into a single sentence with an adjective clause, you must change the pronoun into a relative pronoun like that, who, or which. Pay attention to the position: The adjective clause follows the noun it describes. Look again at the sentence:
- My neighbor, who drives for both Uber and Lyft, knows all of the quick and easy ways to get to the airport.
Here’s another example:
- The car belonged to Young-Hee.
- I bought the car.
How can you combine this into one sentence using an adjective clause? (HINT: What is the same in both sentences? Car.)
Here are two possibilities:
- The car that I bought belonged to Young-Hee.
- I bought the car that belonged to Young-Hee.
There’s no difference in meaning. However, the focus changes. The first sentence focuses the reader’s attention on the car, while the second sentence focuses the reader’s attention on the person buying the car.
Which relative pronoun do you use?
Below are examples of the most common relative pronouns for adjective clauses.
| Pronoun | Use | Examples |
| who | used for humans (sometimes animals) in the subject position
(replaces pronouns like he/she/they) |
Carl is the student who lives near the ocean with his sister Paula.
[Carl is a student. He lives near the ocean with his sister Paula.] Paula, who doesn’t know how to swim, doesn’t like the ocean. [Paula doesn’t like the ocean. She doesn’t know how to swim.]
|
| whom | used for humans in the object position (object of verb or preposition)
(replaces pronouns like him/her/them) |
Somi, whom Carl knows from high school, is a swimming instructor.
[Somi is a swimming instructor. Carl knows her from high school.]
|
| which | used for things and animals in the subject or object position
(replaces pronouns like it/they) |
Swimming lessons, which Somi teaches every weekend, can help Paula.
[Swimming lessons can help Paula. Somi teaches them every weekend.] (object) They all decide to go to the community center, which has a pool. [They all decide to go to the community center. It has a pool.] (subject)
|
| that | used for humans, animals, and things, in the subject or object position | The lessons that Paula needs to learn are important.
[There are important lessons. Paula needs to learn them.] (subject) Carl wants to tell Paula the news that she will pass the class. [Carl wants to tell Paula news. She will pass the class.] (object)
|
| whose | used for humans, animals and things in the subject or object position to show possession
(replaces pronouns like his/her/their/its) |
Somi, whose first language is not English, is happy to help.
[Somi is happy to help. Her first language is not English.]
|
| where | used for places
(replaces a preposition in, on, at or an adverb like here or there) |
Later, Paula wants to swim where there are big waves.
[Later, Paula wants to swim somewhere. There are big waves there.]
|
Try it
INSTRUCTIONS: Combine the sentences using an adjective clause.
- He was sitting in the emergency room. It was very crowded in there.
- A nurse was nearby. He called to her.
- The nurse took one look at the man and knew he needed a doctor. His color was not good.
- She connected the man’s finger to a machine and left him for a minute while she checked another patient. The machine checked his blood oxygen levels.
- Just then, a doctor walked by and noticed that the man had passed out. His finger was still in the machine.
- The doctor took the man’s pulse and temperature and determined that the man likely had COVID and needed a ventilator. It could help him breathe.
- The doctor gave the man an injection. It made him go to sleep.
Is the relative pronoun the subject or the object of the clause?
- Example: The city that she wants to visit most is Berlin.
The relative pronoun that is not the subject of the clause. There is the pronoun she before the verb in the clause, and she is the clause’s subject. The relative pronoun, that, connects the adjective clause back to the noun it describes, which is city. When the subject is not the relative pronoun, you can often delete it, like this: The city she wants to visit most is Berlin.
- Example: There are many drivers who passed a driving test but still do not follow all the traffic rules.
When the subject is the relative pronoun, however, you can’t delete it. In the example above who is the subject for the verb passed in the adjective clause. So this adjective clause cannot be reduced (made shorter).
What punctuation do you need to use with an adjective clause?
Generally, if the adjective clause is helping to identify the noun it describes, then you do not use commas to set it apart.
However, if the adjective clause is only helping to describe the noun but is not identifying it, then you use commas to set apart the adjective clause.
Don’t use commas with clauses that are defining, restrictive, or essential
In the first sentence, as well as describing the woman, the adjective clause who wears a brown dress helps the reader identify exactly which woman the writer is talking about. Similarly, in the second sentence, the clause where my brother used to live helps to identify in which apartment the man lives. In other words, you use an adjective clause without commas when it both describes and identifies the noun. The information is essential to the sentence.
|
Use commas with clauses that are nondefining, nonrestrictive, nonessential
In these examples, Gabriel Reyes and The Japanese Garden are very specific nouns, and the adjective clauses are not required to identify them. These adjective clauses merely provide additional descriptive information. They are not necessary to understand the main idea of each sentence. |
Try it
INSTRUCTIONS: Read each sentence. Add commas where necessary.
- The new coronavirus which causes the disease COVID-19 has infected millions of people globally.
- The disease was first detected in Wuhan where 11 million residents have been living isolated in quarantine for months.
- The disease is spread by droplets which are sprayed into the air when an infected person coughs or sneezes.
- Infection can be transmitted if a person touches objects or surfaces that an infected person has coughed and sneezed on and then touches their mouth, nose, or face.
- Many people who carry and spread the disease show few or no symptoms.
- For people whose health is already impacted by heart disease, diabetes, or other underlying conditions, COVID-19 can be very deadly.
Are there rules for adjective clauses?
| Rule | Do this … | Don’t do this … |
| 1. Always use commas to separate a non-defining/non-restrictive adjective clause from the rest of the sentence. | St. Paul, which is the capital of Minnesota, is situated on the Mississippi River.
Explanation: Do you see the commas? Non-defining clauses need commas. |
St. Paul which is the capital of Minnesota is situated on the Mississippi River.
Explanation: This one doesn’t have the necessary commas. So it’s not easy to separate the main idea from the extra information. |
| 2. Never use “that” as a relative pronoun in a non-defining/non-restrictive adjective clause. | St. Paul, which is the capital of Minnesota, is not the largest city in the state.
Explanation: The relative pronoun, “which”, is correct. |
St. Paul, that is the capital of Minnesota, is not the largest city in the state.
Explanation: The relative pronoun “that” is always wrong in non-defining adjective clauses. |
| 3. Remember to add the relative pronoun when using a non-defining/non-restrictive adjective clause. | We spent time in both Minneapolis and St. Paul, which made it clear the differences between the Twin Cities.
Explanation: This one has a relative pronoun, which is good. |
We spent time in both Minneapolis and St. Paul, made it clear the differences between the Twin Cities.
Explanation: This one forgot to include the relative pronoun “which”, and it is wrong because there’s no subject for the verb “give”.
|
When can you use adjective clauses in your writing?
To connect ideas or to avoid short sentences
- Weaker: The road went to the top of the mountain. It was difficult to use in the winter.
- Stronger: The road, which was difficult to use in the winter, went to the top of the mountain. (or) The road, which went to the top of the mountain, was difficult to use in the winter.
To describe a person
- Weaker: George Spelvin was an actor. He liked to perform in comedies.
- Stronger: George Spelvin was an actor who liked to perform in comedies.
To make writing more concise and more academic
- Weaker: A hashtag begins with the # symbol. It is a label. The label is used on social media sites. The label makes it easier to find posts. Those posts contain specific information or content.
- Stronger: A hashtag, which begins with the # symbol, is a label that is used on social media sites and which makes it easier to find posts that contain a specific information or content.
Did you notice? There are four adjective clauses in the one sentence above! One describes hashtag, two describe label, and one describes posts.
What are some common errors that writers make with adjective clauses?
Here’s one …
- Incorrect: There is an idiom in English: The family plays together stays together.
- Correct: There is an idiom in English: The family that plays together stays together.
Remember to use use a relative pronoun in the subject position.
Here’s another …
- Incorrect: Oregon, that started as a territory, became a state in 1859.
- Correct: Oregon, which started as a territory, became a state in 1859.
Use who, that, or whom for people and that or which for things. Do not use that in nonrestrictive clauses. Do not use whom in a subject adjective clause.
Here’s one more …
- Incorrect: Many people who they have cats also have dogs.
- Correct: Many people who have cats also have dogs.
In an adjective clause, do not include a pronoun that refers to the modified noun.
Practice
Quiz
INSTRUCTIONS: Use an adjective clause to combine each pair of sentences into one sentence.
EXAMPLE:
Item: The flowers have died. We picked the flowers last week.
Answer: The flowers that we picked last week have died.
- The policeman blew his whistle and then shouted at the criminal. He was taking control of the situation.
- Barry is a student at the Cascade Campus of Portland Community College. That campus is in North Portland.
- These new masks help us to stay healthy and safe. They can be used more than once.
- Raphael lost his chemistry textbooks on the bus. They were very expensive.
- Students do well on tests if they are prepared beforehand. Some students are anxious.
- A research paper on environmental problems received an award. I wrote the paper.
- My driveway is in front of my house. I park four cars there.
- The Industrial Revolution changed the way people make things. It began in England.
- Recently, a large airplane had a serious accident. Its engine stopped working.
- The dress was long, black, and beautiful. Mary wore it.
Optional
Use these resources to study more about adjective clauses:
