B. Past Unreal Conditional

Structure:

If ... Past Perfect ..., ... would have + past participle ...

... would have + past participle ... if ... Past Perfect ...

We use the third conditional when talking about things which are contrary to the past facts. In other words: events that did not happen in the past.

Examples:

 • If I had woken up on time, I would have taken the bus.
  (What really happened was that I didn't wake up on time, and so I didn't take the bus.)
 • Tom would have helped us if he had known we were there.
  (What really happened was that he didn't know we were there, and so he didn't help us.)
 • If I had told Sarah the truth, I would have felt much better.
  (What really happened was that I didn't tell Sarah the truth, and so I didn't feel so good.)
 • If it had rained, you would have gotten wet.
 • You would have passed your exam if you had worked harder.
 • If you hadn't lied to me before, I would have believed you.

1. Use "If"

Only the word "if" is used with the Past Unreal Conditional because you are discussing imaginary situations. "When" cannot be used.

Examples:

 • I would have bought that computer when it had been cheaper. Wrong
 • I would have bought that computer if it had been cheaper. Correct

2. Conditional with Modal Verbs

There are some special conditional forms for modal verbs in English:

would have + can = could have

would have + shall = should have

would have + may = might have

The words "can," "shall" and "may" cannot be used with "would have." Instead, they must be used in these special forms.

Examples:

 • Lina might have gotten the job if she hadn't been so nervous.
 • If I had gone to Egypt, I could have learned Arabic.
 • If she had had time, she might have gone to the party.
 • If she had known what to do, she should have told us.

The words "could," should," "might" and "ought to" include Conditional, so you cannot combine them with "would have."

Examples:

 • If I had had more time, I could have exercised after work.
 • If he had invited you, you might have gone.