We use ‘special’ tenses with //when we are talking about ‘unreal’ situations — things that will probably not happen, present or future situations that we are imagining, or things that did not happen. (For example, we can use past tenses to talk about the future.)
- To talk about ‘unreal’ or improbable situations now or in the future, we use a past tense in the if-clause, and a conditional (see 88) in the other part of the sentence.
[ if + past, conditional conditional if + past]
If I knew her name, I would tell you.
(NOT If f would know … NOT … I will tell yott.)
If you came tomorrow, I would have more time to talk.
I would be perfectly happy if I had a car.
What would you do if you lost your job?
We often use were instead of was after if, especially in a formal style.
If I were rich, I would spend all my time travelling.
The difference between if I get and if I got, or if I have and if I had, is not a difference of time. They can both refer to the present or future. After if, the past tense suggests that the situation is less probable, or impossible, or imaginary. Compare:
- If I become President, (said by a candidate in an election)
If I became President, I’d . . . (said by a schoolboy)
If I win this race, I’ll . . . (said by the fastest runner)
If I won this race, I’d .. . (said by the slowest runner)
To talk about past situations that did not happen, we use a past perfect tense (with had) in the if-clause, and a perfect conditional in the other part of the sentence.
- [if + past perfect, perfect conditional perfect conditional if+ past perfect]
If you had worked harder, you would have passed your exam.
If you had asked me, I would have told you.
I’d have been in bad trouble if Jane hadn’t helped me.