If a guy knows a girl likes him and he is always asking people if they hear her talking about him does that mean he likes her because apparently he is interested?

Maybe, but it could mean other things as well. The best way to find out is to ask the guy in question.

obviously

Do noit be stupid of course he likes you my boyfriend did that my brother does that and he is 17 so he lieks you and if you like him ask himout go for it.