The negative of can is can not – cannot. Usually we join these two words together - can’t. In British English we say [ka:nt] and this word is usually stressed: I can’t speak French. She can’t play the piano. In American English the negative of can is usually pronounced [kent]. Pronunciation: it is very important when you are speaking that there is a clear difference between can and can’t. Remember can is usually unstressed - [k..n]. Can’t is usually stressed: I can’t speak French. Ability: I can swim. I can’t speak Japanese. Offering: Can I buy you a drink? Possibility: You can always take a taxi. Suggesting: Can we meet for lunch tomorrow? Requesting: Can we have two coffees please? Permission: Excuse me. Can I sit here? Sloveso can (umět) často používáme, když mluvíme o dovednostech (umím plavat), když něco nabízíme (mohu tě pozvat na skleničku?), mluvíme o možnosti (můžeme jet taxíkem), když něco navrhujeme (můžeme jít spolu zítra na oběd), když o něco žádáme (můžeme dostat dvě kávy?) a když se dovolujeme (mohu si tu sednout?).