How can you tell if a shy guy likes you?

Ask him.

how can you tell if a shy guy likes you?

If you're not upfront enough to ask him does he like you or he's TOO shy to answer.. then the best way is to get close to him and see how he treats you, whether it's a friend-type or a fancy-type. The one thing I don't think you should ask him is 'WHO he likes'.. because you might hear the wrong thing and get put off.. but I believe that anyone can make almost anyone fall in love with them if they know what they're doing, so I say get cracking and good luck :D