how to know if a boy has feeling for u?

there is one boy name cris everone thinks he is the OMG HOTTTTTTTTT,but not me. he always stares at me and tries to talk but can never think of somthing to say and after he says somthing he is like "that was stupid wasnt it?". but why would he chose me and there are like 100 other girls in our grade im not that pretty.