I Swear English › Modal Verbs › May and Might for Speculation
How to form the may and might for speculation
He may well be looking for us by now. I may have lost my keys in the pub.
We can use may and might to speculate about situations and actions in the past present and future. May and might talk about possibilities and so are very suitable for speculating about possible situations. In many ways talking about possibility and speculating are the same thing.
For example: He may have arrived by now, if there wasn't any traffic.
We might be very tired when he gets home.
If I study really hard, I might just pass my exams.
Where is John? He's not here, he may have gone shopping, or he might have gone to his mother's house.
We use may and might when we are imagining the things that people may be doing, or may have done. May indicates a higher degree of certainty than might. In both cases we are indicating that we suspect we know what someone is doing, but that we are not certain. For certainty we use must, or must have. For impossibility we use can't, couldn't, can't have or couldn't have.
MOST CERTAIN must 99,9% > may 50% > might 40% > can't = couldn't 0% IMPOSSIBLE
For example, if you are speculating about where somebody is all of the following are possible but each has a different meaning:
He must be working. He may be working. He might be working. He can't be working.
He must have gone home. He may have gone home. He might have gone home. He couldn't have gone home.
The following video explains May and Might for Speculation:
When to use it
- May / might to speculate about why or how something is, or was. She's late — she may be stuck in traffic.
- May have / might have + past participle to speculate about the past. He didn't call; he might have forgotten.
Signal words & time expressions: perhaps, maybe, it's possible that, who knows, for all I know
Watch the video lesson
Video transcript
Common mistakes to avoid
| Not quite… | Better |
|---|---|
| He didn't answer; he | … he might have forgotten. — to speculate about the past use might have + past participle. |
| She | She may have forgotten. |
Frequently asked questions
How do I speculate about the past?
Use may have / might have + past participle: They might have missed the train.
Is this different from deduction with ‘must’?
Yes — may/might mean ‘possibly’, while must means ‘almost certainly’ and can't means ‘certainly not’.
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This lesson is part of our free English Modal Verbs course — work through it in order or jump to what you need next.