How do I know if a girl likes me?

Eye contact is really a sign. If she does frequent eye contact, or even better, if she smiles at the same time at you is a very good chance she likes you. You know what? If she really likes you, it will take SO little from you to actually get her to open up to you a little.

Start even better, by asking her to have lunch with you while at work. Even if somebody else joins you too. If you start talking, then it will all either fall into place, or you will realize that she may not be into you.

To ask her out you should do it informally, like suggest that you guys go out to get some food or something after work one night as friends. That gives her the space that she needs just in case she doesn't like you like that, it'll prevent awkwardness for her. Her reaction to that question is a good indicator as to if she likes you or not. But when I like a guy I usually stare and smile at him, and I always take an opportunity there is to be around him.

If it were me I would probably ask like things about you, do you have a girlfriend, what do you like to do, maybe we can hang out. I would ask her if she want to hang out for a little bit after work or something then see what happens.

For me, I always catch myself playing around with my hair, and joking around a lot when I'm with the guy I like. If I make eye contact with him from across the room, it either goes two ways. If I am looking at him, and he looks up & sees me, I mouth something to him if I have to be quiet, or roll my eyes if something boring is going on. However if I look up, and I see him looking at me, I look down really quickly, and blush. [I don't know about the girl you like, but I am a huge blusher. ] And as for if you decide to ask her out, do it casually, and make it seem like it's something you would be doing even if she doesn't come (Hey, I was going to go see that new movie this weekend, you wanna come with me? ) that way if she turns you down, it's not like you have confessed your love for her, an who knows, maybe she really just couldn't go. Good luck!