May, might, can are used for permission. Can and may are in the present and future meaning. Might is used in the
conditional and after verbs in a past tense.
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You may go.
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You can go.
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He said you might go.
May is chiefly used when the speaker is giving permission but can is always used instead of may for giving
permission. But it can also be used to express the idea of having permission.
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You may park here. I allow you but the police don’t.
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You can park here. I allow you also police do.
Could, canalso be used for general permission in the past.
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On Sundays we could stay up late.
When a particular action was permitted and performed was/were allowed to is used.
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I had a visa, so I was allowed to cross frontier.
