Question

Which sentence implies that something may not happen?

If I can sing well enough, I'll join the school chorus.

I didn't meet the requirements, so I can't apply for that scholarship.

Why can't you go to the game tonight?

You have a tough decision to make.

Answer 1

The correct answer is if i can sing well enough. The other options are already decided, as in they have an answer.

Answer 2

IF I can sing well enough, I'll join the school chorus.
The IF implies that something is conditional i.e. it may happen, it may not happen (it depends on whether you can sing well enough!)
Hope this helps... :)