How do I know he is interested?

Answer 1

Does he smile when he sees you?

Does he go out of his way to talk to you? (IM you first, call you, etc..)

Does he jokingly make fun of you?

Does he throw in sweet little compliments here and there?

Does he mention you to his friends?

Does he ask you to hang out with him often?

If you can say yes to at least a few of those, he's interested.

Answer 2

There are many subtle things a guy can do that you would need to read... and when you're hoping he likes you, you will usually find body language to support the idea that he does. The most fool proof way is to test the waters. Find a seemingly innocent reason for talking to him and get to know him a little better. Then don't be afraid to come right out and say that you're going to a (movie, sports game, something) that you know he's interested in and you thought he might like to go. If he goes, yeah, he probably is. If he makes an excuse, drop it and find somebody else before you turn into a lovesick stalker! Is he breathing? The better question is what are his goals.

Answer 3

From the point of view of a guy, all you have to do is assume any attempt at communication is some sort of "I'm interested" signal. If somebody expends the effort to talk to someone, chances are they want to communicate.

Answer 4

you feel loved and that he only wants to speak to you and be with you