Rewrite the sentence: I'm sure that Liz hasn't met Harry before. (CAN'T)
Liz can't have met Harry before.
Rewrite the sentence: It would be a great idea if Harry took a holiday. (SHOULD)
Harry should take a holiday.
Rewrite the sentence: What would you advise me to do? (THINK)
What do you think I should do?
Rewrite the sentence: I'm sure they haven't eaten all the food. It's not possible! (CAN'T HAVE)
They can't have eaten all the food.
Rewrite the sentence: It was unnecessary for you to clean the floor. (NEEDN'T)
You needn't clean the floor.
Rewrite the sentence: I'm sure that Helen feels lonely. (MUST)
Helen must feel really lonely.
Rewrite the sentence: Mary knows how to solve the problem. (CAN)
Mary can solve the problem.
Rewrite the sentence: The dentist will see you soon. I don't think he'll be long. (SHOULDN'T)
The dentist shouldn't be long.
Rewrite the sentence: I'm sure that Brenda isn't over thirty. (CAN'T)
Brenda can't be thirsty.
Rewrite the sentence: I think it was the cat that took the fish from the table! (MUST HAVE)
The cat must have taken the fish from the table.
Rewrite the sentence: Do I need a different driving license for a motorbike? (HAVE TO)
Do I have to have a different driving license for a motorbike?
Rewrite the sentence: Jack is supposed to have arrived half an hour ago. (SHOULD HAVE)
Jack should have arrived half an hour ago.
Rewrite the sentence: Helen possibly hasn't left yet. (MIGHT)
Helen might not have left yet.
Rewrite the sentence: Perhaps Pam and Tim decided not to come. (MIGHT HAVE)
Pam and Tim might have decided not to come.
Rewrite the sentence: It was a waste of time worrying, after all! (NEEDN'T)
You needn't have worried after all!
Rewrite the sentence: You needn't come with me if you don't want to. (HAVE TO)
You don't have to come with me if you don't want to.
Rewrite the sentence: You're not allowed to park here. (MUSTN'T)
You mustn't park here.
Rewrite the sentence: It's possible for anyone to break into this house! (CAN)
Anyone can break into this house!
Rewrite the sentence: It was a mistake to park outside the police station. (SHOULDN'T HAVE)
You shouldn't have parked outside the police station.
Rewrite the sentence: I'm sure that David took your books by mistake. (MUST HAVE)
David must have taken your books by mistake.