OK my problem is that I have allot of female friends wich I eventually start liking but don't realize they like me, but when I do finally realize that we like each other its too late because by the time that I realize it they get sick of waiting and are in a relationship what I'm asking is how to know if a girl likes a guy before the opportunity is gone
Plus help

Don't be so shy, if you like a girl, then talk to them more to keep yourself in the picture. When you get a chance, ask them on a date.

How long is "sick of waiting". If they can't wait a bit, then they don't really like you much anyway, so you didn't really loose out.

Try asking the next girl on a group date.

When I was single, I would ask a guy to "meet at ____ with me and my friends". It was a nice way to start without too much pressure. :)

Stop waiting for the girl to make the first move... if you like them, initiate it. Don't sit back and wait for them to tell you that they like you... it is obvious long before THEY ever say it ;)