How to tell a boy I like him?

You poor thing. Do you know how to talk?

I admit I didn't in a similar situation, but talking is the answer. Don't ask us on a website that is world wide -

look at your friend and say what you think. This is part of growing up.

Hi, Dan (or whatever his name is), wanna go get a soda?

And then go, and laugh and talk and have a good time. And unless he's really dense, he will figure out that something is up. Do that a few times and then tell him you like him, although he'll probably have it figured out by then.

Do what you feel is right. Looking into someones eyes and smiling creates an intense connection, it screams on a subliminal basis "I like you."
Ask him how he is and what he has been doing and really listen to him, guys love it when girls take an interest. Yes of course take it slow, you have not seen him for 4 months and you dont know if he is seeing anyone else and you need to weigh up if you still feel the same about him during that time. Things change a lot but if you still connect with him, then keep the eye contact going Good luck