He asks questions about you. 

when a guy likes you he will want to get to know you. How can he do that? By asking you questions. About your work, your family and even about your upbringing and friends.

He gets nervous around you

If he likes you he might act nervous. Nervousness can be shown in different ways by different people. He might talk super fast and not pause for a breath or let you say something. He might stutter. His hands might shake. He might tell dumb jokes.

His body language 

One of the best ways to tell if a guy likes you is to pay attention to what he does with his body when he's around you. Body language has scientifically been proven to communicate attraction.

He shows interest in your interests

He shows intrigue and interests in all the things you're interested in. And he uses those interests as a means to get to know you better.

He notices things about your appearance 

he notices any time you tweak your appearance. The reason is obvious, he stares at you a lot, he's memorized every feature, so of course, he notices when something changes.

He "accidentally" touches you 

He will find ways to touch you, whether overtly or "accidentally." And he will welcome any touches from you.
Pay attention to all signs of physical touch.

He makes eye contact

When a guy likes you, he will look at you. When talking to him, he will most likely make eye contact. This is probably the most intimate you can be with a person without actually being intimate.