Unit 87. Relative clauses (4) – “extra information” clauses (1)

A.
Look again at these examples from Units 84 and 85:

The man who lives next door is very friendly.

Jerry works for a company that makes typewriters.

Have you found the keys (that) you lost?

In these examples, the relative clauses tell us which person or thing (or what kind of person or thing) the speaker means:

“The man who lives next door” tells us which man.

“a company that makes typewriters” tells us what kind of company.

“the keys (that) you lost” tells us which keys.

But not all relative clauses are like this. For example:

Tom’s father, who is 78, goes swimming every day.

The house at the end of the street, which has been empty for two years, has
just been sold.

In these examples the relative clauses (who is 78 and which has been empty for two years) do not tell us which person or thing the speaker means. We already know which person or thing is meant: “Tom’s father” and “the house at the end of the street.” The relative clauses in these sentences give us extra information about the person or thing.

B.
In these “extra information” relative clauses you have to use who for people and which for things. You cannot use that, and you cannot leave out who or which.

When you write clauses like this, you have to put commas (,) at the beginning and at the end of the clause. Study these examples:

Mr. Yates, who has worked for the same company all his life, is retiring next
month.

The strike at the car factory, which lasted ten days, is now over.

When the clause comes at the end of the sentence, you have to put a comma before the clause:

Yesterday I met John, who told me he was getting married.

She told me her address, which I wrote down on a piece of paper.

Remember that we use who/which instead of he/she/it/they:

Last night we went to Ann’s party, which we enjoyed very much, (not which we enjoyed it very much)

C.
You can also use whose, whom, and where in relative clauses with “extra information”:

Martin, whose mother is Spanish, speaks both Spanish and English fluently.

Mr. Hill is going to Canada, where his son has been living for five years.

My sister, whom (or who) you once met, is visiting us next week.
For more information about whose, whom, and where see Unit 86.

See also the next unit for “extra information” relative clauses.