They flirt, they check you out, always stare at you, seem nervous, are kind, do something for you that they usually wouldn't do, always seem to be there, make a point of talking to you.
You'll know when a guy likes you.
No completly true . You wont know always when a guy likes you ....They might act as a friends and keep it a secret like a crush. :)
sumtimes there mean to get ur attention it depends on the guy