 In the episode "My Future Self n' Me" when he starts "Parental Revenge Corp", he speaks Spanish to his Latino workers, though he may have learned the language in order to better exploit a labor pool.He also knows German, and once spoke a few phrases while dressed up as Adolf Hitler while promoting the extermination of Jews to an oblivious audience that did not speak German.Cartman can also be seen speaking broken German with an American accent in Season 15 Episode 2 "Funnybot".