All you really have to do is show her that you care for her and you need to be thoughtful and compliment on things. Just try to show her what you feel for her and she will definitely know what you feel... its a girl thing!
Spend time with her. Listen to what she says. Be interested.
write them a note
you tell a girl you like her by either saying it to her face or getting someone else to say it to her for you
The best way to tell someone you like them, is to just flat out tell them. Don't hold back.
try saying you like her, its not that hard dude.
I am a girl and I would say that you should talk to her first saying, "Why do you like 'Mark'?" and if she says something like... "Becuase he is cute and funny why?" then tell her that you like her and that you could make her happy. If she says no then accept that she is happier like that. its all you can do.
Just tell the girl you like them and she started to like me
You really should say it. But if you really want to cover it up, try saying it in a different language.
Send her a funny card with a little note.
Be straight up with her. Tell her that you like her, or if your the shy type slowly tell her like start out saying that she looks nice today or something like that then after your comfortable saying stuff like that tell her that you like her.
Just tell her or ask her out. If you ask her out then I think she will get the message without you saying straight up "I like you".
text or flirt.