Oxford University Press Walton Street, Oxford 0X2 6DP

you give us the accession number of the book.

Reader: That's the number on the back?

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32 CONDITIONAL CLAUSES PAGE 334

Librarian: No, that's the class number. The number - the accession number -

you'll find if you open the book on the fly-leaf. It's usually about six numbers

at least. And if you'd give us that, the date that is stamped on the date label -

the last date stamped - and your name and address.

Reader: Uh-huh. If I do that, how do I know that it's all right? I mean, if you

want the book back, do you write to me?

Librarian: Yes, we would do that if you had written in, but of course, if you'd

telephoned or called in we could tell you then.

(from M. Underwood Listen to This!)

Conditions express different degrees of reality. For example, a condition can be

open or unreal.

Open: If you join the library, you can borrow books.

Unreal: If you'd arrived ten minutes later, we would have been closed.

An open condition expresses something which may be true or may become true.

(You may join the library). An unreal condition expresses something which is not

true or is imaginary. (You did not arrive later.)

NOTE

A condition can also be definitely true.

I'm tired. ~ Well, if you're tired, let's have a rest.

The meaning here is similar to You're tired, so let's have a rest.

2 We can use conditional sentences in a number of different ways: for example to

request, advise, criticize, suggest, offer, warn or threaten.

If you're going into town, could you post this letter for me?

If you need more information, you should see your careers teacher.

If you hadn't forgotten your passport, we wouldn't be in such a rush.

We can go for a walk if you like.