Prvním

Prvním is a form of the Czech ordinal adjective první, meaning "the first." It is used to express order and to describe the first item, moment, or position in a sequence, often appearing in phrases that specify time, place, or relation.

Grammatically, adjectives in Czech decline for gender, number, and case. Prvním is the instrumental singular form of první for masculine and neuter nouns, as in s prvním dnem or s prvním mužem. It also occurs as the locative singular form after appropriate prepositions when referring to masculine or neuter nouns, as in v prvním patře. In feminine phrases the instrumental singular form is unchanged: první, as in s první ženou. The feminine locative and instrumental forms differ in some contexts, so feminine usage follows the independent feminine form.

Examples illustrate its use: s prvním dnem (with the first day), s prvním mužem (with the first man), v prvním patře (in the first floor), and s první ženou (with the first woman). These forms show how prvním signals the masculine or neuter gender in instrumental or locative constructions, while in feminine phrases the form is první.

Etymology and related forms: první comes from the same root as cognates in other Slavic languages, such as Polish pierwszy and Russian первый, all deriving from a common Proto-Slavic origin meaning “first.” In Czech, prvním is specifically the instrumental/locative singular form used with masculine and neuter nouns.

See also: Czech grammar of ordinal numbers; the declension of adjectives in Czech.