could somebody please tell me if there is some kind of difference between the words, wether it be register or meaning? As I speak Polish pretty well already, I know how to use the word coś (which seems to correspond to Czech něco), but today I've learned that there's also the word cosi, which I had never seen before. I know a song of Ewa Farna where she sings "Mám chuť ukázat něco víc." (Mam ochotę pokazać coś więcej.) A friend of mine said he wouldn't use něco there and would prefer cosi. So, is there any difference between them?