You don’t have to / mustn’t wear hiking boots during the walk. It isn’t far and the paths are good. Wear trainers if you prefer.
don't have to
20
Students ought not to / needn’t leave their bags in the corridor because they may cause an accident.
ought not to
20
We’re flying to the USA on Sunday. Do you think I must / should exchange euros for dollars before we go?
should
20
According to safety regulations at the safari park, visitors mustn’t / needn’t leave their car windows open at any time.
mustn't
20
We aren’t supposed to / needn’t leave the school grounds at break time, but a lot of students go out to buy sweets at the shop across the road.
aren't supposed to
20
You have to / should use this key to open the door. It’s the only one that will work.
should
20
Which modal verb can not be used in this sentence? With a bit of luck, we can / may / might be able to reach the campsite before nightfall.
can
20
Which modal verb can not be used? I have no idea where the dog has gone. He could / might / must be hitchhiking to Australia for all I know!
must
20
Which modal verb can not be used? The bus for Corinth must / might / could be about to leave, but since I don’t have the timetable, I can’t know for sure.
must
20
Which modal verb can not be used? That might not / can’t / must not be Louisa’s guidebook. Hers is new, I think, and that looks a bit old. I’d ask her just to check.
must not
20
This path must / can / should lead back to the hotel. It’s the only route there is.
can
20
Harry has already left. I think he (might / must / should) __________________________________ (catch) the nine o’clock train, but I’m not sure.
might have caught
20
Sylvia (can / should / may) __________________________________ (tell) us that she was going away. It was really bad of her to let us down in this way.
should have told
20
You (can / might / must) __________________________________ (give) me a lift! Didn’t you see me on the side of the road?
might have given
20
William (can’t / needn’t / shouldn’t) __________________________________ (know) about the trip. If he had known, he would have definitely come with us.
can't have known
20
You (weren’t supposed to / didn’t need to / mustn’t) __________________________________ (tell) Andy about the birthday party when you did. His sister wanted it to be a surprise.