Genitiv: des, der, eines

The genitive shows who something belongs to or what it is part of, like English "of" or "'s": das Auto meines Vaters (my father's car).

• masculine and neuter: des, eines, meines, and the noun adds -s or -es (des Vaters, des Hauses, eines Kindes)
• feminine: der, einer, meiner, and the noun does not change (der Lehrerin, meiner Schwester)

Possessives follow ein: meines, deines, seines, unseres for masculine and neuter, meiner, deiner, ihrer, unserer for feminine. Nouns ending in -s, -ß or -z must take -es (des Hauses, des Platzes); many one-syllable nouns can (des Buches).

The genitive also follows prepositions like wegen, während, trotz and innerhalb: wegen des Wetters (because of the weather), während des Unterrichts (during the lesson). In speech, von + dative often replaces it, but written German needs the genitive.