Answer: We give you extra attention. That is pretty much what it comes down to. We don’t have any secret thing we do if we like you, we just spend more time with you.
Flirting is a part of it, we will probably flirt with you more, and find more opportunities to flirt with you.
More contact and touching. When we like someone, we want to be around them, and we want to touch them. Usually we will touch you more while we talk, we will hug you when we greet, we will put our arm around you, or sit close to you on the couch. Basically we are going to look for opportunities to touch you more. This is not sexual, but we will offer you massages, or we will put our hand on your back when you leave a room before us, or we will stand with our hand on your shoulder, etc. Physical contact is a big indicator that we like you, especially if we are not touching other people as much.
We make an effort to talk to you, and probably tease you more. When we like a girl we try to get to know her better, and get a feel for her feelings for us, so we are going to seek out opportunity to talk to you. This might mean taking a different route to our classes so we walk by you in the hall and have a chance to talk to you. It might mean sitting by you at lunch. In addition to talking, we will probably tease you. That is one of the tools in our flirting arsenal.
Inviting you to do stuff, not necessarily dates, but as part of a group is another thing we will do if we like you. If we like you, we want to make sure you are where we are, but usually we do not want it to be too obvious, so we will invite you to group stuff, or we will make sure you get invited. For example, we might say, “There is a party tonight, maybe I will see you there.” We usually act non-committal as to whether or not we will even be there.
If you are wondering if a guy likes you, it is really not that hard to tell. If he is hanging out with you and is being nice to you, there is a good chance he is interested in some way. If a guy is interested in you, he is going to approach you, spend time with you, etc. He isn’t going to try and be your best friend, per say, but at least find a way to spend time around you. So clue in, if he did not spend much time with you or talking to you before, and he is now, he probably likes you!