Nothing. He is being nice. Say hi back.
Well first you need to know if he is a nice guy. If he is your chances are that if you walk bye and randommaly say hi, he will say hi back. If he's mean he might not say hi back because he doesn't know you.
Say hi back!
guys hit each other to say hi, idk why. but why would u do that ? probably, i will feel bad or annoyed, or sumthing, if someone said hi to someone n not me. idk why. but probably. n more if he stares at u, its like saying "Arent u going to say hi to me too?" Well my answer is Proabably yes.
It means that he likes you but he might be a little shy to talk to you! Do you say hi back, if not, start talking back to him?
It means that he wants you to notice him, but doesn't think that you REALLY do
Just say hi, to be on the safe side. . .
Go up to him and say hi
No, it just means he doesn't have a horrible memory
You might have to do it yourself.
go near him and count to 10 in your head and then when he looks at you then say hi
he is upset at you for something, or you insulted him, or someone said you insulted him