How to tell if a guy friend likes you!
I've been pretty much researching this topic. I couldn't help but feel somewhat disappointed, in what there is sometimes; because the signs of a guy liking you, consistently don't apply to me! Maybe, it's because your crush is a fair mix of introvert-extrovert and therefore had mixed behaviors. Not everyone in the world solely shy or outgoing, just saying. Sometimes it is both!
Signs he takes a genuine interest in you
If he pokes you, is mean, teases you and doesn't mind hugs; he probably likes you more than a friend, but has no idea how to express it. One of my guy friends, when I initiate a hug - he does not let go, until I do. If the guy in question does this, he probably has strong, romantic feelings for you. If he tries to prevent you from letting go of a hug...he uh, pretty much loves you. With evenly introvert-extrovert guys, you know they are popular and confident. (extrovert) But if he doesn't try to chat you up constantly or doesn't always check of you're okay when you are sad...don't take it personally, he could be shy and not want people to know he likes you. If he's around people a lot you'll find this happens a lot. Either that he is clueless in what to do sometimes or he respects you and gives you space, so he doesn't always try to linger. He may not want to appear annoying, it's not that obvious though - so to detect that, you must be a keen observer. Nevertheless, he is your friend so he will talk to you and be friendly. That's enough to appreciate, in my opinion.
If say you suddenly make it awkward, or go through an awkward silence; if the guy in question, doesn't mind and keeps talking to you because you're keeping your cool and continuing the conversation - he is probably very interested in you and isn't overly judgmental. Of course all friends put up with awkward stuff you say...but if this happens more than once or twice, it's likely that they take a more-than-a-friend liking towards you. I know that from experience.
And if for some reason, he does not ask for your number, talk to you at all on Facebook or text you; (if you have his number) don't worry, it's not because he doesn't like you. He is your friend, so as long as in real life he still treats you like a friend all the time, online if he does not converse to you - don't take it too personally first of all. Maybe he's like that with everyone online! (if you do know that he IMs other people, you might be stalking him...) He might also just not be into IMing in general or does not want to make it obvious he likes you, by always talking to you on and offline. (if so, he is pretty smart and has self-control.)
Due to his introvert-extrovert even split personality...sometimes he'll act unshamefully teasing, boastful and talkative; other times (especially when you run out of stuff to say) he is nervous, silent / quiet, avoiding eye contact yet still walks next to you or is with you. A clever one knows, that he'll make it obvious that he likes you - if he makes you jealous often, by being around other girls (hugging them even!) or asks you if you are single / taken. And you see, they are the things he absolutely won't talk about or do a lot because he knows you will get the picure and eventually figure out he likes you. If you have any other concerns with introvert-extrovert guys, wondering if they like you - feel free to message me and I'll help you out willingly. Good luck and be optimistic!