It takes a lot of confidence and courage to ask a girl out on a date, but there's less risk of embarrassment if you know the girl has similar feelings. Look for these signs to determine if she's got a crush on you to increase your chance of success.
Study the girl's behavior when she talks to you. If she fidgets with her hair or jewelry, laughs enthusiastically at all of your jokes or frequently touches your hand, shoulder or playfully pushes you, she's probably interested.
Consider her topics of conversation. She may be establishing a foundation with you by discussing how long you've known each other, how much your families are alike or the extracurricular activities and interests that you share.
Watch her friends when she's talking to them across the room. If they're taking quick glances at you or even giggling and nudging her after looking at you, they're most likely talking about you. If you glance at her and she quickly looks away, she may be worried that you've caught her looking.
Ask her friends if the girl likes anyone. If they're blunt, they may admit that she likes you. If she's sworn them to secrecy, they may giggle or give you a cryptic answer.
Notice if she suddenly starts showing up near your locker between classes, at the library while you're studying or on the athletic field while you're practicing, for example.
Catch her reaction when you talk to other girls. If you have a crush on her, however, try not to use this technique too many times or as an attempt to make her jealous. She may lose interest if she thinks you're untrustworthy, that you prefer to play the field or that you're interested in someone else.