Question

Tomorrow I'll give a speech in front of the class.
I'm so nervous.
1. I could forget everything.
2. I may forget everything.
3. I might forget everything.
4. I can forget everything.
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In this situation, which one is suitable?
What is the difference between #1 and #2? In #1, 'could' was used. In #2, 'may' was used. When do you use 'could'?

Answer 1

There is not much difference among 1, 2, and 3. All are referring to possibilities.

4 is also referring to a possibility in a way, but seems a bit more likely to happen -- as if the speaker would will it to happen!

I'd use #3.