"Can do it" versus "could do it"

Question

What is the difference between these sentences?

I can do it.

I could do it.

Answer 1

It depends on the context. The difference is clearer when you look at a question. "How could I better my speaking skills?" vs "How can I better my speaking skills?". The first seems like a personal request for help, while the latter seems like a question wanting a factual answer or a list. So to answer your question, "can" is used to ask for or state facts, while "could" generally is more personal. Usually the context makes it clear.