Article: If he's always looking at you, he might like you. If he follows you or walks faster to be next to you, he might like you. Preferably, one of the people in your group.

What is a summary?
Look to see if he's looking at you every few minutes. If  you both are in a group, walk a little ahead of them. Get someone to ask him who he likes. Ask other people that hang out with you two if they've noticed any signs of him liking you.