It isn't necessary for her to phone me back.
She needn’t phone me back.
Perhaps we'll go swimming tomorrow.
We may/might/could go swimming tomorrow
I think Mary is probably at home because the windows are open.
Mary might /may/could be at home because the windows are open
Perhaps John knew about the trip, but I'm not sure.
John may/might/could have known about the trip, but I'm not sure.
Perhaps we'll rent our house in summer.
We may/might/could rent our house in the summer.
You cannot smoke in the underground; it's forbbiden.
You mustn’t smoke in the underground.
It is essential that we talk before the meeting starts.
We must talk before the meeting starts.
Why don't we go on a camping trip?
We could go on a camping trip.
Let's go to Diagonal Mar!
We could go to Diagonal Mar.
It isn't necessary for us to book a table; I know one of the waiters.
We don’t need to book a table; I know one of the waiters.
It's forbbiden to drive without fastening your seatbelt.
You can’t drive without fastening your seatbelt.
If I were you I'd do some more exercises.
You should do some more exercises.
Perhaps I go on holiday to Menorca
I may/might go on holiday to Menorca.
I'm sure something is happening tonight. Look at those preparations!
Something must be happening tonight. Look at those preparations!
