Add have + past participle to talk about the past. For guesses: She must have missed the bus. He might have forgotten. They can't have seen us. For regrets and criticism: I should have left earlier. You could have told me!
The ground is wet. It must have rained.
The certainty gauge, looking back: must have means you're almost sure it happened.
| must have + participle | Almost certainly happened: He must have left. |
|---|---|
| might / may / could have | Possibly happened: She might have called. |
| can't / couldn't have | Almost certainly didn't happen: They can't have finished already. |
| should have | It was the right thing, but it didn't happen: I should have studied. |
| could have | It was possible, but it didn't happen: You could have asked me. |
The lights are off. They must have gone out.
A strong guess about the past, based on evidence now.
I can't find my keys. I might have left them at work.
Might have, may have and could have all mean it's possible.
She can't have seen us. She didn't say hello.
You're almost sure it didn't happen.
I should have booked earlier. Now it's sold out.
It was the right thing to do, but you didn't do it.
You could have told me you were coming!
It was possible, but it didn't happen. Often a complaint.
Common expressions worth learning as they are.
The road is wet. It _____ in the night.
How sure, how necessary, how polite.
Paste an email or an essay. Clarigram marks the mistakes you actually make, shows the rule behind each one as a picture, and builds your practice from them.
No. It comes from the sound of should've. Always write should have, could have, would have.
Yes: She could have taken the train means it's possible she did. The context tells you whether it's a guess or a missed chance.