Czech (his passport) changes endings all over the place. It's how our grammar works. Nouns and adjectives have different endings depending on their contextual gender associations. Czech last names are either adjectives (rarer), in which case the male form ends with ý and the female form ends with á (the latter generally denotes femininity), or nouns, in which case the female form gets turned into an adjective with the ová ending. For example, if your last name is Kovář == Smith, your wife's or daughter's last name would be Kovářová, which could be loosely translated as "of Smith" or "of Smith material" (Kovářka would be the Czech noun for "a female Smith", but female noun surnames don't turn up in formal Czech -- though they make reasonable abbreviations/nicknames among friends). Czech has also the very similarly sounding ova ending (as opposed to ová) which literally denotes possession in addition to the female gender (Kovářova == a (male) Smith's). This doesn't turn up in Czech last names, but it does in other Slavic last names (notably in Russian last names), which makes it sound familiar. Whether it also denotes possession in those languages, I don't know.