Modal Verbs: May/Might

Modal verbs in English grammar express the ability, permission, obligation, possibility, etc. Modal verbs only have one form, meaning that they are used in simple present and don't have past simple and past participle forms.

However, some modal verbs can have alternative forms which can be used in different tenses.

Permission

Rule 1: We can use both may and might to ask permission in present simple. May and might are more polite than could.

Note: We usually only use may in questions with I and we.

Rule 2: We can only use may to give permission.

Possibility

Rule 3: We can use both may and might to express possibility in the future. There is no difference between may and might.

Note: We rather don't use contractions with may not and might not.

Deduction

Rule 4: We can use both may and might when we think something is most likely true, but we are not 100% sure.

Rule 5: We can use may/might (not) + have + past participle to speculate about something.