Unit 8 perfect infinitive

3. Must have + Past participle
Express a deduction about something
that has happened. We feel quite sure
about it.
I didn’t hear her voice. She must have gone out.
I couldn’t find them. They must have moved

4. Might have + Past participle Express a past possibility.
You might have heard some noises when my car was stolen.
He might have bought food for all of us.

5. Could have + Past participle
That was dangerous; she could have called the police.
She was so close; she could have come to home
Express past reference about
something that was not carried out.

6. Peter should have asked you before borrowing your laptop.
We should have eaten after leaving the place
Express the idea that something was
desirable or needed but didn’t take
place
Should have + Past participle
.

7. I would have bought a car if I had saved money last year.
He would have built his house if he had sold the cars
Express something in the past that
did not happen. (Third conditional)
.
Would have + Past participle

8. They can’t have passed Joe’s exam.
She can’t have found that by herself.
Express a deduction about
something that did not happen in
the past based on present evidence.
Can’t have + Past participle