Asking a single girl out

Hi guys i 17 year old male. I have a friend that i like and i asked her if she wanted to be my girlfriend 2 years ago. she said she already had a boyfriend but we still remained friends. i still haven't forgotten her over the years. Right now she is single. How do i find out if she likes me now? and any tips on how to get her to like me? plz help. thanks

Question From: pete - Sep 2nd 2009