The genitive case
Genitive is German's possessive case: it answers wessen? ('whose?'). Where English says 'my father's car', German says das Auto meines Vaters — literally 'the car of-my father'. The owner sits AFTER the thing owned, and gets genitive endings. Genitive also follows a small group of formal prepositions: wegen (because of), trotz (in spite of), während (during), statt / anstatt (instead of). In everyday spoken German, dative often replaces genitive (das Auto von meinem Vater) — but for B1 reading and writing, the genitive forms are essential.
The basic possession pattern
Possessed thing (any case) + owner (genitive). The owner follows. das Auto meines Vaters = my father's car. die Tasche meiner Mutter = my mother's bag. das Buch des Kindes = the child's book. die Häuser der Eltern = the parents' houses. The owner phrase carries the genitive marking; the rest of the sentence treats the whole noun phrase normally. Ich sehe das Auto meines Vaters. = I see my father's car (object — accusative on the outside, genitive on the inside).
Article and adjective endings in the genitive
Definite articles: des (m./n.), der (f./pl.). Indefinite / possessive: eines (m./n.), einer (f.); plural with possessives meiner / deiner etc. After a der-word, adjectives in genitive end in -en: des alten Mannes, der alten Frau, der alten Leute. After an ein-word, also -en for all genders: eines alten Mannes, einer alten Frau, meiner alten Eltern.
Noun endings in the masculine and neuter genitive
Masculine and neuter nouns add -s or -es in the genitive singular. One-syllable nouns prefer -es: des Mannes, des Kindes, des Tages, des Hauses. Multi-syllable nouns usually take just -s: des Vaters, des Computers, des Lehrers. Feminine and plural nouns get NO ending — only the article changes: der Frau, der Mutter, der Kinder. Names get -s without an apostrophe: Annas Buch, Toms Auto (English-style apostrophes are wrong in standard German).
The four genitive prepositions
These four are the classic genitive prepositions in formal German: wegen (because of), trotz (despite), während (during), statt / anstatt (instead of). wegen des Wetters = because of the weather. trotz der Kälte = despite the cold. während des Tages = during the day. statt eines Briefes = instead of a letter. In speech these often slide to dative (wegen dem Wetter) — common but considered nonstandard. Stick with genitive in writing.
Genitive vs. dative in everyday speech
Spoken German is replacing the genitive in two big places: (1) the prepositions above (wegen dem Wetter instead of wegen des Wetters) and (2) possession itself. Where writing says das Auto meines Vaters, speech often says das Auto von meinem Vater — von + dative. Both are understood, but only the genitive form is fully accepted in formal writing. A famous half-joke book title — Der Dativ ist dem Genitiv sein Tod — captures the trend (and the colloquial 'dative + sein' possessive that purists dislike).
Genitive after certain expressions
A handful of fixed expressions still take genitive even in modern German: eines Tages = one day, eines Morgens = one morning, letzten Endes = ultimately / in the end, meiner Meinung nach = in my opinion. Notice the genitive -s even on feminine eines Nachts = one night (irregular — survives from older usage).
Genitive question word: wessen?
wessen? = whose? — the genitive of wer. Wessen Buch ist das? = Whose book is that? — Das ist Annas Buch / das Buch meiner Schwester. It's the most direct way to flag a possession question. In speech you'll also hear Wem sein Buch ist das? but that's strongly colloquial — use wessen in writing and clear speech.
