Non-defining relative clauses

Non-defining relative clauses

We use non-defining relative clauses to give extra information about the person or thing. It is not necessary information. We don’t need it to understand who or what is being referred to.

We always use a relative pronoun (who, which, whose or whom) to introduce a non-defining relative clause (In the examples, the relative clause is in bold, and the person or thing being referred to is underlined.)

Clare, who I work with, is doing the London marathon this year.

Not: Clare, I work with, is doing the London marathon this year.

Doctors use the testing kit for regular screening for lung and stomach cancers, which account for 70% of cancers treated in the western world.

Alice, who has worked in Brussels and London ever since leaving Edinburgh, will be starting a teaching course in the autumn.

Warning:

We don’t use that to introduce a non-defining relative clause:

Allen, who scored three goals in the first game, was the only player to perform well.

Not: Allen, that scored three goals in the first game, was the only player to perform well.

See also:

• Relative pronouns

Punctuation

In writing, we use commas around non-defining relative clauses:

Etheridge, who is English-born with Irish parents, replaces Neil Francis, whose injury forced him to withdraw last week.

Spoken English:

In speaking, we often pause at the beginning and end of the clause:

Unlike American firms – which typically supply all three big American car makers – Japanese ones traditionally work exclusively with one maker. (formal)

And this woman – who I’d never met before – came up and spoke to me. (informal)

Defining or non-defining relative clauses?

Sometimes defining and non-defining relative clauses can look very similar but have different meanings.

Compare

non-defining	defining
His brother, who works at the supermarket, is a friend of mine. He has only one brother, and that brother works at the supermarket.	His brother who works at the supermarket is a friend of mine. He has more than one brother. The one I’m talking about works at the supermarket.
It’s hoped that we will raise £10,000 for local charities, which help the homeless. The money is intended for local charities. All these local charities help the homeless.	It’s hoped that we will raise £10,000 for local charities which help the homeless. The money is intended for local charities. Some of these local charities help the homeless. There are other local charities as well as these.

Warning:

The information in a defining relative clause is essential, so we can’t leave out the relative clause. The information in a non-defining relative clause is extra information which isn’t essential, so we can leave out the relative clause.

Compare

The soldier who had gold stripes on his uniform seemed to be the most important one.	A defining relative clause which we can’t leave out; without this information we do not know which soldier the speaker is referring to.
The tour party was weakened when Gordon Hamilton, who played in the World Cup team, withdrew yesterday because of a back injury, which kept him out of the Five Nations Championship.	Non-defining relative clauses which we can leave out: The tour party was weakened when Gordon Hamilton withdrew yesterday because of a back injury.

Warning:

We can use that instead of who, whom or which in defining relative clauses, but not in non-defining relative clauses:

I think anyone who speaks in public is nervous beforehand.

I think anyone that speaks in public is nervous beforehand.

Her car, which was very old, broke down after just five miles.

Not: Her car, that was very old, broke down after just five miles.

EJEMPLOS

• John's mother, who lives in Scotland, has 6 grandchildren.
• My friend John, who went to the same school as me, has just written a best-selling novel.
• My grandmother, who is dead now, came from the North of England.
• We stopped at the museum, which we had never visited before.
• I've just come back from London, where John lives..
• Yesterday I met a woman named Susan, whose husband works in London.

• He gave me the letter, which was in a blue envelope. (proposición explicativa: había solo una carta y era azul. Es necesario emplear "which")
• He gave me the letter which/that was in a blue envelope. (proposición especificativa: había varias cartas de distintos colores y él me dio la azul. "Which" puede sustituirse por "that". Las comas desaparecen.)
• He gave me the letter, which I read immediately. (proposición explicativa: había solo una carta. Aunque "which" es el objeto de "read", debe incluirse en la oración.)
• Stratford-on-Avon, which many people have written about, is Shakespeare's birthplace. (Las preposiciones suelen colocarse al final de la oración de relativo.)
• Stratford-on-Avon, about which many people have written, is Shakespeare's birthplace. (En inglés escrito formal, también es posible colocar la preposición antes del pronombre.).