Cazzo

The expression Col cazzo is used to violently contradict what was being discussed, like “my arse” in English (“Col cazzo che vincerete la partita!” = “You’ll win the match, my arse!”). 

Col cazzo is also used as an interjection (“Vieni a casa mia?”, “Col cazzo!” = “Are you coming at my place?”, “I’m fucked if I do!/Forget it!”). 

Sto cazzo (literally meaning “This dick”) has essentially the same meaning as col cazzo, but it’s only used as an interjection. The same expression at plural, Sti cazzi, is used to express admiration and/or surprise as in, “Ho vinto alla lotteria!” - “Sti cazzi!” (- I won the lottery! - Wow!). The same expression, in other regions is used to show lack of interest in something, like “I don’t give a fuck” in English (“Ho vinto alla lotteria!” - “Sti cazzi!” = “- I won the lottery! - …like I give a fuck!”).

The expression Grazie al cazzo (lit. Thanks to the dick) is used to address a trivial statement, as in ” - Parla inglese molto bene. - Grazie al cazzo, sua madre è inglese!” (“He speaks very good English. - Not surprising, his mother’s English!”).

Also used to reinforce a question (“Che cazzo è?” = “What the fuck is it?” or “Chi cazzo sei?” = “Who the fuck are you?”) and even as an interrogative pronoun in its own right (“[Che] cazzo vuoi?” = “What the fuck do you want?”, or “[Che] cazzo ti frega?” = “Why the fuck do you care?”). Using “cazzo” in this sense signals anger or aggressiveness.