if a girl likes you: She will flirt with you, play hard to get, twirl her hair ect.
if a boy likes you: He will flirt with you, chat you up, talk to you ect.
if I like you: I will stalk you from a distance, make note of everyone you talk to (your friends, family ect.), I will get to know your interests and never, ever will I attempt to make a move. Then I will proceed to buy cats.