do you like him? if you don't, just ignore his actions.
if you are interested, can try getting close to him. e.g. talk
about common interests? sports? hobbys? movies etc.
after that, den maybe ask him out casually. go shopping?
lan-games? movies? and observe his reaction to ur invitation
lor.
and if you really really want the answer and is interested in
him. just tell him straight.
tell him you like him and ask him whether he feels the same for
you. unless the guy has no interest in the girl, it is unlikely
that he will reject a girl.