Hope vs hopes

[Gobo]

When I look up the noun hope in my dictionary, I see that it is both a countable and an uncountable noun. How do I know when it is countable and when it is uncountable?

[Anglika]

Usually by the context of the sentence.

My hope is that I will pass my exam.
There is no hope for the survival of the dodo.

I have great hopes of the future.
The hopes and fears of all the years are met in you tonight.

[Gobo]

Thank you :)