If you are not sure whether someone has a crush on you, maybe it's because you don't know the telltale signs.
If someone holds eye contact with you for a long period of time, chances are good that he has a crush on you. A person's pupils dilate when she is looking at someone she's attracted to, according to a study conducted by Chicago University. This has nothing to do with the light in the room, said Dr. Eckhard Hess. It's an involuntary action.
Words speak loudly when it comes to a crush. The person will want to engage you in conversation and hang on your every word. You don't even have to say anything of importance; he will still listen to every word and make comments when appropriate.
How a person moves can tell you if he has a crush on you. She will move in close to you during conversation, or tilt her head to one side to capture your every word.
How a person sits and stands can give hints of a crush. A man will stand straight, with his chest out, and a woman will continually cross and uncross her legs.
Women are known for their hand movements when they have a crush on a man. She might flip her hair, put her hand closer to yours or touch you when you have said something funny or meaningful. Men talk more with their hands when they're trying to describe something to impress a woman.
When someone has a crush, he will take more care with his appearance. A man will want to be clean shaven or rough looking, depending on his heart's desire. A woman will spend more time on her hairstyle, make-up and clothes.