Why is '' speaking five languages'' a general ability?
I saw these examples in the grammar book, it says:
1.My grandfather could speak five languages.
2.We were completely free. We could do what we wanted.(=we were allowed to do...)
The explanation to the first example is we also use could to say that somebody had the general ability or permission to do sth. So now I am wondering about what '' general ability'' really is, does it mean ''ordianry abiltiy"? if it does, I believe from the view of most people, a person who can speak five languages is more capable than an ordinary person.
The explanation to the second example is even more ridiculous from what I can see, because it happened in the past, so obviously we should use "could" instead of "can".
Many thanks for your answers.