Page 207 - Advanced English Grammar in Use

C o n d i t i o n a l s e n t e n c e s ( 1 ) : v e r b t e n s e s

Some conditional clauses beginning with if suggest that a situation is real - that is, the situation
is or was true, or may have been or may become true:
• If anyone phones, tell them I'll be back at 11.00.
• If you really want to learn Italian, you need to spend some time in Italy.
Others suggest that a situation is unreal - that is, the situation is imaginary or untrue:
• What would you do if you won the lottery?
• If you had started out earlier, you wouldn't have been so late.
Compare:
• If I go to Berlin, I'll travel by train. (= real conditional) and
• If I went to Berlin, I'd travel by train. (= unreal conditional)
In the first, the speaker is thinking of going to Berlin (it is a real future possibility), but in the
second, the speaker is not thinking of doing so. The second might be giving someone advice.

Real conditionals
In real conditionals we use tenses as in other kinds of sentences: we use present tenses to talk
about the present or unchanging relationships, and past tenses to talk about the past:
• If you leave now, you'll be home in two hours. • If water is frozen, it expands.
• If I made the wrong decision then I apologise.
However, when we talk about the future, we use a present tense, not will (see Unit 100):
• I'll give you a lift if it rains, (not ...if it will rain...)

Unreal conditionals
In unreal conditionals, to talk about present or future situations, we use a past tense (either
simple or continuous) in the if-clause and would + bare infinitive in the main clause:
• If my grandfather was/were still alive, he would be a hundred today.
• If you were driving from London to Glasgow, which way would you go?
• I'd (=would) offer to give you a lift if I had my car here.
Notice that we sometimes use if...were instead of if...was (see Unit 100).
When we talk about something that might have happened in the past, but didn't, then we use if
+ past perfect and would have + past participle in the main clause:
) • If I had known how difficult the job was, I wouldn't have taken it.
* • If she hadn't been ill, she would have gone to the concert.

In unreal conditionals, we can also use could/might/should (have) instead of would (have):
• If I lived out of town, I could take up gardening.
• They might have found a better hotel if they had driven a few more kilometres.
In some unreal conditionals we use mixed tenses. That is, a past tense in the if-clause and would
have + past participle in the main clause, or a past perfect in the if-clause and would + bare
infinitive in the main clause:
• If Bob wasn't so lazy, he would have passed the exam easily.
• If the doctor had been called earlier, she would still be alive today.

Notice that in unreal conditional sentences:
• we don't use the past simple or past perfect in the main clause:
• If we were serious about pollution, we would spend more money on research, (not ...we
spent... or ...we had spent...).
• we don't use would in an if-clause (but see Unit 100):
• If I had a more reliable car, I'd drive to Spain rather than fly. (not If I would have...)
Conditionals (2) => IIDIlllilil If...not and whether => IIDIllliH