The guy is normally cool, but it seems like every time he's around you, he fumbles around and stutters a lot. If he can barely look you in the eye when he speaks, he definitely likes you.
He may touch you a lot when he's talking. You know he's interested if he's constantly hanging on you in a playful manner or he takes time to brush the hair out of your face.
You know he likes you if he spends more time with you than with his buddies or his car. He rearranges his schedule so he can take you out to dinner. When he cancels the poker game with his friends to take you to the movies, he's definitely into you.
You're playfully arguing with his best friend. He takes your side and agrees with you that, yes, women are smarter than men. It's a sign of interest when you're more important than his entire gender.
If you're on your first date and he either takes your number to call you for another date or he asks for a second date right then and there, he is interested. He's trying to set a time and place to continue getting to know you better.
Every time you run into him, he has a new compliment for you. He likes your hairstyle or he thinks the dress you're wearing compliments your perfect figure. He's completely infatuated when he says something like, "My day has just gotten better" as you walk into the room with him.
He calls you for no specific reason and just wants to talk, or he pops by your house unannounced only wanting to chat. When he texts, sends instant messages or emails you on a regular basis about trivial things, he's interested in you.
Offer of Help
He is always offering to help you do things, such as carry your bag to class or fix your computer at work. If he despises calculus, for example, yet wants to come over to help you study for the final, he is really into you.
You tell him about your bad day. He is there to offer his support with either a pick-me-up talk or a quick trip to the ice cream shop for a pint of cookies n' cream. You know he likes you when he blows off a big night, such as the Super Bowl, to come over and make you feel better with a pizza and a movie.
He's told you things, such as he still sleeps with his baby blankie or that he cried when Apollo Creed died in Rocky IV. A guy is genuinely interested in you when you know things his buddies and his family don't even know.