Some other verb

Can

Can for represent the ability of the subject.

a) can in present.

1) I can cook.
2) Can you cook?
3) I can not cook.

b) can in past

1) I was able to cook yesterday.
2) Were you able to cook?
3) I was not able to cook.

c) can in future

1) Tomorrow I will be able to cook.
2) Will you able to cook?
3) I will not be able to cook tomorrow.

Permission

1) You are not allowed to smoke here.
2) You are not allowed to take photos
3) You are not allowed to speak here.

Probability and possibility

a) Strong Probability almost 100 percent

1) It must be an ashtray.

b) Strong improbability 100 percent

1) It can not a be shoe.

c) uncertain probability 50 percent

1) It might be water box.
2) It could be a computer.

Used to

Used to use for the habit of the subject.

a) positive form

1) I used to smoke.
2) I used to play tennis.
3) I used to wear fur.

b) negative form

1) I did not use to take vitamins.
2) I did not use to listen to opera.

c) negative from

1) I  did not use to do a lot of sports.
2) Did you use to stay in bed until midnight?

Question tag

Question tag use for confirmation from subject.

1) You are married, are not you?
2) You did not go to part, did you?
3) He lives in London, does not he?
4) They are not French, are they?
5) She went to the cinema, did not she?
6) You do not like him, do you?
7) They were enjoying the show, were not they?
8) He is coming tomorrow, is not he?
9) They will be late, will not they?
10) We can not buy it, can we?