Opportunities

Can/could may be used to talk about possibility:

a) theoretical possibility: It can be quite cold here in summer. In this sense could suggests a less definite possibility: It could rain later this evening.

b) possibility due to existing laws: People can marry here when they are eighteen.

c) possibility due to circumstances or to choices and opportunities: You can have the book when I have finished it. There are several ways out. You can go to the police, you can visit a lawyer or you can forget all about that. What shall we do tomorrow? – Well, we could go fishing.

Can/could expressing possibility is used only with the Indefinite Infinitive.

Russian constructions могло (бы) быть и хуже, могло (бы) быть и лучше expressing possibility or impossibility with comparative adjectives are rendered in English by could and Indefinite Infinitive: The situation couldn’t be worse. It could be better.

Can is not found to talk about future probability – the chances that something will happen: may/might express this idea. (See Unit 3)

§ 3 Can/could to express uncertainty, doubt,