how can i ask out my best friend?

Question

we've been friends since we were born and now i like him, but how can i tell him i like him without loosing our friendship

Answer 1

You want to untie (loose/loosen) your friendship? How odd.
I think you fear LOSING your friendship.

Ask him if he would like to do [specific activity] at [specific time and date]. In this way you can get to know each other better without having to make a commitment, and you can learn better how much you like him. You don't even have to call it a "date."