May can express the following meanings:
- Permission or asking for permission (formal).
- May I interrupt you?
- You may be seated
- The form might is used in indirect speech according to the rules of the sequence of tenses
- He told me that I might go home
- Prohibition (formal)
- You may not smoke in here
- Possibility due to circumstances like can (only in affirmative sentences with an indefinite infinitive)
- You may/can order a ticket by telephone
- Uncertainty. Might is less categoric
- He may be tired
- He might come later
- May or might are used with all forms of the infinitive. The Perfect Infinitive is used to refer the action to the past
- He may/might have sold the house
- They might not be working in the library now
NOTE: Supposition or uncertainty in questions is rendered by: Is he likely to…?, Is it likely that he …?, Do you think…
- Is Mary likely to arrive tonight?
- Reproach, hurt feelings (only might is used)
- You might at least say you’re sorry
- You might have warned me!
- May you be happy!
Here are a few important rules for modal verbs:
- Modal verbs do not take any endings like -s, -ed or -ing
- Modal verbs are followed by the base form of another verb (may do, might be)
- Modal verbs make questions by inverting the subject and the modal verb (may I)