Any girl can be polite and friendly when you strike up a conversation with her, but if she really likes you, the conversation will take a playful and flirtatious turn. She'll laugh at your jokes and go out of her way to compliment you. Some girls might take the less obvious approach and tell you they enjoyed watching you score the winning goal at your soccer game, but other girls can be a little more forward. If she leans in and whispers that you look great in your green shirt, take note that she's definitely interested in you.
So, where do you go from here? Talking to your crush through text messages and Facebook is one way to go. It's less intimidating than a face-to-face conversation, and you have plenty of time to come up with answers to tough questions and to think of something clever. The best advantage, because you can't see the other person's facial expressions, is that the nervous knot in your stomach won't be there.
Even if you tend to get anxious in situations that require face time, try talking to the girl you like in person, too. You don't want to look like you lack self-confidence because you retreat to your computer as a crutch. Also, don't expect a girl to accept a date if you asked her out by writing on her Facebook wall. And while sending coy texts is an acceptable way to flirt in a relationship, resist the urge to confess your love or ask a girl to an important event through a text message. Remember, you want her to feel special, and the only acceptable way to ask her out is by collecting yourself, taking a deep breath and calling her on the phone -- or, better yet, finding a time to ask her out in person. She'll be flattered and appreciate your sincerity.