well you can never really tell but... you can notice something different that they are doing such as talking to you more, complementing you and just being nicer also having the time to get to know you a little more so if the guy is doing any of these i think you should start too and see where it goes:)
you can tell if his penis moves when hes around you
Cause he is sexy!!
he gets a boner
ask him for money
be a man the end from Carly
if you look at him and hes looking at you and quickly looksaway ,he probably likes you .or he tries to be around you alot then he likes you.
Tell her to bag up of your man
man up and ask her
tell him to chose who he likes best or if you want a man who likes only you then say go chase after that hoe you like.
Tell him that you didn't ignore him...
if he looks straight in your eyes, that means he likes u.
Use your female intuition. There's no other waay .