What (I, do) ... about it? You ... be more careful.
What shall I do? You should be more careful.
What must I do? You have to be more careful.
When you are here again, you really ... come and see us.
must
should
Dogs ... kept on a lead
must/should
can/could
She ... live there; at least, her car is always standing outside.
They ... leave the neighborhood because of that scandal.
had to
I ... tell him something. I ... wait until he arrives
have to - have to
should - should
... (you, cut) your fingernails at table?
Do you have to...
Do you should...
It is certain that he will be washing the car when we arrive.
He is bound to be washing the car when we arrive.
He must be washing the car when we arrive.
Did you hear the bang? No, I ... (be) in the other room.
must be
should be
It wasn't raining. You ... (take) your umbrella.
needn't have taken
haven't had taken
I haven't got my gloves. I ... (leave) them in the car.
must have left
have had left
How did he get away? He ... (use) his car, because it's still here.
cant have used
mustn't have used
I saw Jones yesterday. You ... (see) Jones. He's in Canada.
can't have seen
mustn't have seen
You.. (leave) a spanner inside the engine. That's why it's making such a rattle.
can have left
I left my car here. It's gone. Someone ... (steal) it.
must have stolen
should have stolen
He ... (do) such a thing. It's impossible.
can't have done
mustn't have done
He was sleeping. He ... (sleep) - he ... (pretend)
can't have been sleeping - must have been pretending
must have been pretending - can't have been sleeping