Summarize this article:

Though there's no sure fire way to know if the guy returns your feelings, there are a variety of signs that can let you know how he really feels about you. It's best to make sure that there's at least a chance that he likes you before you move on and tell him how you feel about him. If showing him that you like him just isn't doing the trick, then it may be time to tell the guy how you feel about him. You should pick a time and place where you can both be alone and free of stress, and then keep cool as you tell him that you have feelings for him. Don't put a lot of pressure on him or yourself and wait for a response. If the guy likes you, then you can hug him or just show him how happy you are, and begin to talk about going on a date and moving your relationship forward. If he doesn't return your feelings, that's OK too -- just show him how mature you are by not getting too upset, or even getting angry, because he doesn't share your feelings. If it turns out he likes you, then you can even laugh about all the ways that you tried to show him that you liked him. If he doesn't like you, don't despair. Be proud of yourself for working up the courage to share your feelings and move on.
Make sure that he likes you. Tell him that you like him. React appropriately.