English language - coudl you tell me sthg,...

Could you tell me what is (is it at all?) a difference between 'my friend' and 'friend of mine' ? Or there is absolutely no difference and we may use them interchangeably every time, inevery case?

A friend of mine is probably better.

"My friend" is more accepted because it's shorter and more casual. They mean the same thing though.

Are you trying to show off about the number of friends you have?wii4panta