I quoted these two sentences from my grammar book.
So, I have no context.
Without more context it is hard to tell what the difference is between the two sentences--if any. The first sentence might mean that while she cannot give a big concert this year she can do so next year. However, the second sentence could mean the same thing. There is really no reason to believe that the two sentences mean two different things.
Then, you use these two sentences without any distinction?
Isn't there some difference of a nuance, or some difference of a tendency of a use?
I thought that when a speaker states B, he or she dosen't have confidence than when he or she states A.
A:She can give a big concert next year.
B:She will be able to give a big concert next year.
A:I can visit you tomorrow.
B:I will be able to visit you tomorrow.
My guess is not right?
Thank you for your time.