How can being shy not be an issue?

I’ve liked this guy in my year for over a year now and I used to find it easy to talk to him when we were in the same class. He knew I liked him and when I girl asked him if he liked me he said yes. But that was last year now and we’re not in the same class any more and things have become awkward. He is very shy but laughs and smiles at me the majority of the time and sometimes I catch him trying to look at me in the one class we still have together. And when he’s talking to friends and I walk past he’ll immediately fall silent. But I’m not sure if he likes me or he’s just being polite because I’m generally the one to start the conversation. I mean we’re not ‘close’ friends and we don’t live that close to each other and don’t hang out at lunch as he plays football. Is it because he’s shy or what?
I can’t tell if he likes me, it’s seriously annoying as it’s been a year. Any help is much appreciated. xx