You have been talkin to this girl for a while and you know she likes you and you feel the same way you dont want to write a poem you just want to say something really sweet to her so she likes you mo?

Compliment her. Say her clothes are cool, and if they're not then say something like 'you must be really pleased about that top/skirt etc... Say her hair looks nice and say she must be a good hairdresser to have such a cool hairstyle. She might get shy and look away and that is the sign she likes you.