I'm not sure if you mean, like, shaking or shivering, but that's the only way I've ever heard it used .... but I may be wrong :P X
It sort of tells the girl that you like her back.
She does not like him
it definintly does
it means he trusts you he might like you
It could mean the girl finds him to be caring, and could even like him.
that mean they don't like him
It probably means that she would like to kiss you.
it means that she thinks that you like her and she likes you to
He likes the girl he kisses unless it was an he didn't mean to kiss that girl. or he likes the girl he kisses and lies and says he like someone else
He really likes you!!!!
They are most likely talking about themselves liking you.