Does he like me? Non awkward convo?

Last year I told him I liked him and he started to avoid me. But this year I have him in one of my classes and he gives off the body language that he likes me, suck as pointing his body towards mine, looking at me, and subconsciously copying my body language. We had to hold hands for a class thing and his hands got sweaty. But how can I tell if he likes me? And how can I start a convo with him on fb that wont be awkward if he doesn't like me?