Men and women may be from different planets, but there are still ways to interpret the signals they send each other. When observing the male of the species, watch what he says and does around you. If you don't have any idea if he likes you, try to interact with him more. If he flirts or responds to you, he probably likes you. You could also have friends ask him if he likes you. (This is more common in high school or junior high.) The quickest way to find out is to ask him out. When you are dating, watch his body language. Obviously physical signs such as holding hands and kissing should mean that he is interested.