Ability Logical conclusion Necessity Obligation Permission Possibility Prohibition Requests Advice

Can, could I can remember all my friends telephone numbers. He could swim by the time he was 3.

Cant be, must be Ann isnt answering the phone. She must be out. This cant be the South Pole.There arent any penguins.

Must/cant have V 3 You must have been tired after all that hard work last week. You cant have been tired last Sunday – you slept for hours.

have to, dont have to I have to cycle to school. Its too far to walk. I dont have to go to school today – its a national holiday.

Must, mustnt You must do this homework carefully. You mustnt steal other peoples things. Its wrong.

Had to We had to stay behind after the lesson and do some extra work.

Can, could, may You can borrow my bike, but you cant have the car. Could my friends come to stay next weekend? May I speak loud here?

May, might Ann is not in class. She might be in the library. Sam may come to the cinema with us – Im not sure if hes free.

Mustnt Students mustnt use a dictionary in the exam.

Can,could, would Can you tell me the time, please? Could you pass me the salt? Would you mind pouring me some water?

should You should write to your family.

Should have V 3 You should have written to your family.(but you didn't.)

Could have V 3 You could have tried a new method (but you didn't choose to.)

Ability Advice Requests Prohibition Possibility Permission Obligation Necessity Logical conclusion should can mustnt may must have to must be could might

Ability cancould

Possibility maymight

Necessity have to

Logical conclusion must be

Requests can could

Obligation must

Advice should

Permission can could may

Prohibition mustnt