Modals of speculation

Why were there no buses yesterday? Maybe it was the snow or they _____ on strike.

• must have been

• might have been

• can't have been

Do you remember my birthday party last year? You _____! It was the same day as your graduation.

• can't remember

• could remember

• must remember

Let's ask at reception to see if they have your keys. Someone _____ them.

• must have found

• could have found

• couldn't have found

Whose coat is this? It _____ Paul's. It's way too small for him.

• must be

• may be

• can't be

He _____ to Russia. He didn't have a passport.

• must have gone

• could have gone

• can't have gone

Oh no! My phone's not in my bag. I _____ left it at home.

• must have left

• can have left

• couldn't have left

The house isn't hard to find. It's the red one at the end. You _____ it!

• might miss

• might have missed

• can't miss

• can't have missed

Where's Clare? Her bag's here and her computer's still on so she _____ home.

• must go

• must have gone

• can't go

• couldn't have gone

I can't remember my password! But I _____ it in my notebook as sometimes I do that.

• may write

• may have written

• can't write

• can't have written

That _____ the vegetarian option. It's got chicken in it.

• must be

• must have been

• can't be

• can't have been