Men who are emotionally unavailable may be great listeners, but they're not necessarily good talkers. They're not willing to open up and communicate, or share their feelings openly. Often, this is because they've grown up in a household that exhibits this same type of behavior. If your man's parents prodded him to be silent and strong instead of intuitive and honest, he may be used to and comfortable with shielding his emotions, both from you and from himself.
Emotionally unavailable men can be much more drawn to the chase and getting the girl than they are to actually having a relationship. Once this man knows that he's got you hooked, he'll lost interest. If you back off and appear unavailable yourself, he'll be interested again. However, this may not be a cycle that you want to be involved in.
Some men are emotionally unavailable because they're actually in another relationship aside from the one with you. You cannot get much of a commitment from a man who's committed to another woman, whether he has a girlfriend, or a marriage and family. These men want you in their lives at certain times, but ultimately they won't make you their priority.
It's not always a negative character trait or history that makes a man emotionally unavailable. Some men just have interests that don't include being in touch with their feelings. For example, men who seek out adventure, love to travel and take risks for entertainment may be emotionally unavailable because they prefer to concentrate on other areas of their lives that don't include romance.
A man with a large ego may be emotionally unavailable. If the man is attractive, he may have grown up feeling that he could get what he wanted on looks alone. He may have never had to develop an emotional side because women gravitated to him without it. On the same note, if your guy's very into himself, he may not be putting any thought into your feelings, or his feelings for you and your relationship.