Mea culpa is pretty common and translate similarly in Brazil (minha culpa), after all, portuguese is a language that has latin as an ancestor, but my favorite and the one that confused me the most the first time I saw is "Quod erat demonstrandum", almost all mathematical proofs that I did in college had Q.E.D. instead of the portuguese C.Q.D. at the end to indicate that that was the point where the proof was finished.