Proto-Slavic *pьrvъ

→ Bulgarian първи (inherited)

→ Bulgarian пръв (inherited)

→ Czech prvý (inherited)

→ Kashubian piérwi (inherited)

→ Old Church Slavonic прьвъ (inherited)

→ Macedonian прв (inherited)

→ Polish pierwszy (derived)

→ Russian первый (inherited)

→ Istro-Romanian prvi (derived)

→ Serbo-Croatian prvi (inherited)

→ Serbo-Croatian први (inherited)

→ Slovak prvý (inherited)

→ Slovene prvi (inherited)

→ Silesian piyrszy (inherited)