Sometimes my father has the difficulties to understand me and my friend. Sometimes I can not understand the words which my sister (7 years younger) says. Young people use a slang, new words, new "bad" words, which we use just among our friends. For example the word "ZAJEBIŚCIE" - polish young people use it very often and for us it means that something is cool, great, wonderful... For my dad this word is "bad" one (the true is that this word comes from Russia and in russian language it means something completely different..., but there is no many young people who speak russian and they don't know the "roots" of this word...). But in the school, at the university, in the offices, in discussions with older people we use normal words