Could

COULD Ability I could speak China when I was seven. Could you swim when you was nine? She couldn’t get a job anywhere.

COULD Possibility This team has good performance this

season. They could be a champion. You should take an umbrella,

it could rain later. Mary couldn't be the one who stole the

money.

COULD Request Could you please open the window? Could you give me a ruler, please?

May

May For suggest something will happen - There may not be  many people there. - We may be late for the meeting.

Use may to suggest situation that happen in the past

- May / Might + have + V.3 (Past Participle) - She may have gone out when I phoned her

May use may not for a refusal it is emphatic - You may not borrow the car until you can be more careful with it.

to make polite requests or ask for permission

- May I borrow the car tomorrow? - May we come a bit later? - May I ask you a few question?

Can or May ? When you ask for a permission…. Can I ask you a few questions? wrong

May I ask you a few questions?

Can should only be used in expression to do with ability.

MightMore usual than mayWhen we are not sure about something.

Structure: S + might(not) + infinitive/V.ing

Examples: - I might not be there tomorrow. - It might rain today.

Use might to suggest small possibility. - We might have a party next week.As the past tense of may for requests Example: - She asked if she might borrow the pen.As the conditional of may Example: - If I entered the contest, I might win.

Might

For permission Examples: - Might I sit here? - Might I ask you a question?

Might

Might not It suggests you don’t know if something

happens. Example: - She might not be at the school today.

Might