Polski — Neuter noun declension

Polish neuter nouns end in -o (okno), -e (morze), -ę (imię, cielę) or -um (muzeum). Each takes a full set of endings across the seven cases, in both singular and plural.

How it works

✓ Rule

In the nominative plural, -o and -e become -a: okno → okna, morze → morza. The ending -ę expands its stem: imię → imiona, cielę → cielęta. Nouns in -um do not change in the singular (muzeum stays muzeum in every case) but decline normally in the plural: muzea, muzeów.

Full paradigm (okno)

Declension of okno (window)
Case	Singular	Plural
Nominative	okno	okna
Genitive	okna	okien
Dative	oknu	oknom
Accusative	okno	okna
Instrumental	oknem	oknami
Locative	oknie	oknach
Vocative	okno	okna

Good to know

⚠ Note

The genitive plural is the trickiest form. It usually has a zero ending with a stem change: okno → okien (an -e- is inserted), morze → mórz (o → ó), imię → imion, cielę → cieląt. Only -um nouns add -ów: muzeum → muzeów.