He establishes direct eye contact. An interested man will like staring at your eyes during a discussion, whether he maintains a glance or turns away as your eyes connect. If he's bashful, he'll probably look down to avoid making eye contact. Check out this article about male eye contact for additional information. He listens with interest and expression on his face. Shy guys are usually very good at listening to what you have to say but don't want to over-commit themselves to the conversation. If you feel like he's paying attention to you without being too attentive, that's how it signals that he's interested. He smiles. A shy guy who is interested in you will definitely have some smiles thrown in there from time to time. Although small smiles don't do much for most people, they can help make a shy guy less intimidating and more approachable. He nods. When you're talking about something serious, or if you need him to understand something clearly, he'll probably nod occasionally. It's his way of showing agreement without appearing rude by saying "yes" or "no." He takes notes. If you are discussing something important or relevant to his career, he might jot some things down to look them up later. This shows that he is engaged and interested in what you have to say. He asks questions.