ability, possibility or obligation?

We couldn't wait to see you next week when you come to visit us.

I'm determined to work for the company for as long as I'll be able.

A lot of my friends have taken their driving test but only a few can pass it on the first attempt.

The bus got so hot that I felt I can't breathe any more.

They wouldn't afford to buy new clothes except on rare occasions.

The student study centre isn't as good as it has to be, given the cost of the fees.

When we arrived at the college, we must find our own accommodation.

If you live a long way away, you are able to stay at the college hostel.

I am very sorry but I really couldn't be at the airport when you arrive.

We don't have to forget how hard women fought to get the vote.