5 things about non-defining relative clauses

Dan, who is an excellent teacher of English, has a handful of tips to help you learn and use non-defining relative clauses. Learn them, love them and they'll never let you down!

DanHi Guys! Dan for BBC Learning English here. This time we're going to be taking a look at non-defining relative clauses and why they are awesome! Are you ready? Here we go.

Number 1 – they're free. How cool is that? They are like the free toothpaste you get given when you go to a shop and buy a toothbrush. You don’t need it, but everybody likes something for free. What’s even cooler is, if you don’t want it, you can remove itand the main information from the sentence is the same.

Number 2 - you can always identify them! Unlike sneaky defining relative clauses,non-defining relative clauses are always marked with commas next to the noun which they describe. When being spoken, the intonation pattern of the sentence changes to show where the clause is. For example, 'The pens which I left on the table were stolen.' 'The pens, which I left on the table, were stolen.'

Number 3 - they are proud. Unlike shameful defining relative clauses, which can hide their relative pronoun or use ‘that’, non-defining relative clauses always use the correct relative pronoun - who for people and which for objects. AND they never omit them.

Number 4 - they can count! Non-defining relative clauses are able to quantify a noun, even if the main clause doesn’t. They can be used with determiners such as many, some, all, a few, half etc. This allows us to comment on part of a group rather than all or nothing – like defining relative clauses. 'The pens, many of which I left on the table, were stolen.'

Number 5 - they care about our opinion! Non-defining relative clauses are not only able comment on a noun within a sentence, but allow us to make a comment on the whole sentence itself. This is used to communicate the speaker’s opinion about the events they’ve just mentioned. 'The pens, which I left on the table, were stolen, which surprised me.'

Aren't they cool? Learn them, love them and they'll never let you down. Non-defining relative clauses – a speaker's best friend.

Summary

1.  You can remove a non-defining relative clause and the sentence will still make sense. Itadds extra information about the noun.

• Their dog, which spent its first year living on the streets, didn't like sleeping in the house.
• Their dog didn't like sleeping in the house.

2. You can always identify a non-defining relative clause because there is a comma after the noun it's describing. There will always be a comma at the end of the non-defining clause as well unless it finishes the sentence.

• Her hair, which was naturally brown, was dyed blonde.
• She had blonde hair, which was dyed.

3. Non-defining relative clauses always need the correct relative pronoun (which, who, whom). In defining relative clauses, these pronouns are often replaced with 'that'. It's also not possible to leave the pronoun out of a non-defining relative clause.

• Correct: Their car, which was 20 years old, had begun to fall apart.
• Wrong: Their car, that was 20 years old, had begun to fall apart.
• Wrong: Their car, was 20 years old, had begun to fall apart.

4. Non-defining relative clauses can add extra information about the quantity of objects described. We do this by using expressions such as many, some, all, a few, half followed by the correct relative pronoun.

• The people, half of whom had never voted before, elected a new leader.
• The patients, many of whom smoked, were suffering from lung conditions.

5. You can comment on a whole sentence using non-defining relative clauses.

• The pigeons, which were all over the town square, left a terrible mess, which was disgusting.
• The children, who were having a wonderful time, didn't want to go home, which didn't surprise me.

Grammar Reference

Relative clauses

Meaning and use

Relative clauses are used to give additional information about a noun, such as a person, place or thing. Relative pronouns introduce a relative clause. They include who for people, that and which for things, when for time, and whose to show possession.

 Relative clauses belong to one of two categories: defining relative clauses and non-defining relative clauses.

1. Defining relative clauses add essential information to a sentence.

The woman who found my wallet handed it in to reception.

The student whose dog has run away has gone to look for it.

I remember the day when we first met.

These are the earrings that my mother gave me.

These clauses give essential information about the subject of the sentence. They define the person, time or thing that we are talking about. If we remove the clause, the sentence does not make sense.

2. Non-defining relative clauses add extra information to a noun or noun phrase.

My friend’s birthday, which was last weekend, was great fun.

My current girlfriend, who I love very much, calls me every night.

This extra information is not essential. If we remove the clause, the sentence still makes sense. This type of clause is more common in written English.

Form

Defining relative clauses are made with noun + relative pronoun + rest of clause.

A kangaroo is an animal which lives in Australia.

The man who came for lunch was my uncle.

Winter is a time when it sometimes snows.

Non-defining relative clauses are made in the same way. An important difference, however, between both types of clause, is the use of punctuation. With non-defining relative clauses, we separate the clause with commas. We cannot use that in this type of clause.

My favourite food, which used to be Italian, is now Japanese.

Rachel, who we met yesterday, lives in this neighbourhood.

My car, which I bought seven years ago, needs replacing.

This shirt, which I bought last weekend, cost £50.

My best friend, who I met at university, is coming for dinner.

Take note: replacing the relative pronoun

In informal communication, relative pronouns, such as who and when, are commonly replaced with that in defining relative clauses.

The woman that called last night was very polite.

Do you remember the time that you first met?

Take note: leaving out the relative pronoun

When using defining relative clauses in informal speech and writing, the relative pronoun can be left out completely if it refers to the object of the relative clause.

This is the shirt that I bought.

This is the shirt I bought.

The girl who I like isn’t here yet.

The girl I like isn’t here yet.

In non-defining relative clauses, the relative pronoun cannot be left out.

Take note: spoken English 

The relative pronoun who is used when referring to people. However, in formal written and spoken English, if the pronoun refers to the object of the clause, we use whom instead.

My German teacher, whom I really admired, retired last year.

The woman whom I called this morning was my secretary.

Non-defining relative clauses

Part of a sentence which adds extra information about the noun.

5 things about them:

1.  They add extra information about the noun.

• Their dog, which spent its first year living on the streets, didn't like sleeping in the house.

2. There is a comma before and after the clause.

• Her hair, which was naturally brown, was dyed blonde.

3. Use the correct relative pronoun.

• Correct: Their car, which was 20 years old, had begun to fall apart.
• Wrong: Their car, that was 20 years old, had begun to fall apart.

4. They can add extra information about the quantity of objects described. 

• The people, half of whom had never voted before, elected a new leader.

5. You can comment on a whole sentence.

• The pigeons, which were all over the town square, left a terrible mess, which was disgusting.