Notice if he takes an interest in your life. Does he ask about your hobbies? Follow up on things you told him you were going to do? Does he make an effort to get to know your friends? Does he try to learn about your family or where you grew up? These are signs that he's interested in you.
Consider how he talks about you. You should also pay attention to how he talks about you. How does he describe you when he introduces you to other people. Introducing you at all is a good sign, since if he really doesn't care about you it probably won't even occur to him. However, if you're dating you should be worried if he is reluctant to call you his girlfriend. If you're friends, look for the tone of voice he uses when he says that you're his friend. Is the word emphasized? That's not a very good sign either.
- A guy who's really interested and really cares will rush to introduce you using the most familiar term that he thinks he can get away with because he's proud and excited that you like him enough to be around him.
