Dr. Grammar says:

“What’s wrong with this sentence? I like movies, which are funny and romantic.”

It would be a good idea to look at the grammar lesson “Relative Clauses – Introduction” first.

EXPLANATION

We saw in the article “The Great Wall of Vietnam” that there are two types of relative clauses: defining relative clauses, and non-defining relative clauses. In ‘Wedding Day Disasters’, we can see a number of examples of both types. So what is the difference between them? Let’s look at two example sentences:

1. Dogs which are intelligent may be used to help people in a variety of jobs.

2. Dogs, which can be very intelligent, are popular pets.

It is easy to see which one is defining and which is non-defining by looking for commas. A defining relative clause is not separated from the noun by a comma, but a non-defining relative clause is. So which sentence is defining and which is non-defining?

1. Dogs which are intelligent may be used to help people in a variety of jobs. = defining

2. Dogs, which can be very intelligent, are popular pets. = non defining While the relative clauses of these two sentences are quite similar, the meaning of them is very different. To help us understand the difference, answer this question:

Which dogs are the two sentences describing?

1. Dogs which are intelligent may be used to help people in a variety of jobs.

This sentence is describing dogs which are intelligent, not all dogs.

2. Dogs, which can be very intelligent, are popular pets.

This sentence is describing all dogs.

This means:

A defining relative clause tells us which things we are describing.

A non-defining relative clause just gives us extra information about something.

Let’s look at a second example and try to answer the same questions for the following two sentences:

Which sentence is defining and which is non-defining?

Which school pupils are the two sentences describing?

1. The school pupils who cheated in an exam were punished.

2. The school pupils, who cheated in an exam, were punished.

1. = defining

    = only the pupils who cheated (there are some other students who didn’t cheat)

2. = non defining

    = all pupils (so they all cheated)

Some extra information about relative clauses:

1. Use defining relative clauses to be more specific about what/who you are describing.

2. Use non-defining relative clauses to add extra information about any noun or noun phrase in your speaking and writing.

3. In speaking “that” can be used to replace “which”, “who” or “where”, but should not be used in non-defining relative clauses (ie, don’t put a comma before “that”).

4. In writing, choose “which”, “who” or “where” instead of “that” because they are more formal.

EXERCISE

Combine the following sets of sentences to make a single sentence using a relative clause, and decide if the clause is defining or non-defining (do not include the information in brackets (…) in your sentences:

1. I like cats and have three at home. Cats are excellent hunters.

2. Some workers were fired. They were fired because they stole from the company (but other workers were not fired).

3. My dad loves listening to music. My dad likes to relax.

4. Vietnamese food is becoming more and more popular around the world. Vietnamese food is healthy and delicious.

5. The young adults got good jobs. They got better jobs because they studied at university (but the other young adults didn’t study at university, and they didn’t get good jobs).

Answers:

1. I like cats, which are excellent hunters, and have three at home. (non-defining)

2. Some workers who stole from the company were fired. (defining)

3. My dad, who likes to relax, loves listening to music. (non-defining)

4. Vietnamese food, which is healthy and delicious, is becoming more and more popular around the world.

5. The young adults who studied at university got better jobs.

FURTHER PRACTICE

Read the story “Wedding Day Disasters” and locate any relative clauses. Now decide if they are defining or non-defining, and analyse which nouns or noun phrases are being described.

Afterwards, try to make some sentences of your own using defining and non-defining relative clauses. You can use these nouns and noun phrases to help if you want:

the Internet                             Christmas                                          Valentine’s day

my family                                 the countryside in Vietnam             mobile phones

This material is provided by the Australian Centre for Education and Training (ACET).