modals permission and obligation test

Paul is behaving in a very unusual way. I think he ______ again.

• can't drink

• can be drinking

• might be drinking

Answer explanation

might be drinking

➪ He might be drinking again = 'Perhaps he is drinking again.'

I think there ______ a mistake in your tax return. You should check it.

Choose TWO correct options

• can't be

• might be

• may be

Answer explanation

We can use might or may to say that we think something is possible but we’re not sure.

There could be a mistake = 'Perhaps there is a mistake.'

If Suzan said that, it ______ true. She never lies.

• might be

• must be

• can be

Answer explanation

must be

It must be true = 'I'm sure it is true.'

You ___________ go to the ceremony if you don't feel like it. It'll be very boring anyway.

• haven't to

• don't have to

• mustn't

Answer explanation

don't have to

don’t have to + infinitive = to say that something is not necessary.

We took too much risk. We______________ that decision.

• needn't have made

• mustn't made

• shouldn't make

Answer explanation

needn't have made

When something was not necessary but we did it,

He _________________ the bus because his brother picked him up at the station.

• needn't have taken

• shouldn't have taken

• didn't need to take

Answer explanation

didn't need to take

When something was NOT necessary and we did NOT do it, we use didn’t need to (NOT needn't have done).

We couldn't find a hotel so we _______________

in the car. It was so uncomfortable!

• had to sleep

• must have slept

• should have slept

Answer explanation

We had to

We need to express past obligation, and had to is the only form we have in this sentence to do it.

We should have slept in the car means 'we didn't sleep in the car but it was the right thing to do'.

We must have slept in the car means 'I'm sure we slept in the car'.

We _____________early because it was a holiday, so we slept till late.

• didn't have to get up

• needn't get up

• needn't have got up

Answer explanation

didn't have to get up

When something was not necessary but we did it.

However, when something was NOT necessary and we did NOT do it, we use didn’t need to (NOT needn’t have done).

What is the difference between these sentences?

I can speak five languages.

Bill and Tom can't help you.

What is the difference between these sentences?

I must buy flowers for my mother.

I have to buy flowers for my mother-in-law.