How can i tell if a guy likes you?

i go to taekwondow with him, he fixes his hair infront of me when im waiting for the teacher, he also smiles at me and i think he pretends that he doesnt like me my cuzen told meh that he likes me and when im not at taekwondow he talks a lot about me and when im not he doesnt say nothing about me does he like me , also he laughs wwith someone else and loos at me as he laughs sometimes. does he like me please help