definite articles (der, die, das...), indefinite articles (ein, eine ....), kein- and possessive articles (mein, dein, sein ....) in the nominative, in the accusative, in the dative and in the genitive case:

The genitive case is used 

 

•  to express possession and a sense of belonging to, e.g.  

Das ist das Buch meiner Schwester. (This is my sister's book.)

Die neue Freundin meines Bruders ist sehr nett. (My brother's new girl-friend is very nice.)

Die Zahl der Studierenden ist gestiegen. (The number of students has risen.)

 

 

Note: with proper names and family-member terms used as names (i.e. father, mother, brother, sister), German adds an -s without an apostrophe, e.g.

 

Julias Fahrrad ist rot. (Julia's bike is red.)

Wolfgangs Augen sind braun. (Wolfgang's eyes are brown.)

Vaters Auto ist kaputt. (Father's car is broken.)                                                                

Mutters Apfelkuchen schmeckt fantastisch. (Mother's apple cake tastes wonderful.)

 

 

Note: If the name ends in an "s" - sound (-s, -ß, -z, -tz), no "s" is added. In writing, the omission of this "s" is indicated by an apostrophe. When speaking, a construction with "von" + dative is used instead of the genitive, e.g.

 

Markus' Garten ist sehr groß. / Der Garten von Markus ist sehr groß. (Markus' garden is  very big.)

 

 

• after prepositions that always take the genitive case, e.g.

Anstatt des Hauses bekam sie nur 50 000 Euro von ihrem Onkel. (Instead of the house she only received 50 000 from her uncle.)

Trotz des schlechten Wetters gingen sie spazieren. (Despite the bad weather they went for a walk.)

Dank seiner finanziellen Hilfe konnte sie studieren. (Thanks to his financial help she was able to study.)

Während des zweiten Semesters hatte er viele Probleme. (During his second semester he had a lot of problems. )

Wegen der Wirtschaftskrise gingen viele Firmen bankrott. (Because of the economic crisis a lot of companies went bankrupt.)

 

• for expressions of indefinite time, e.g.

eines Tages (one day)

eines Morgens (one morning)

eines Abends (one evening)

eines Nachts (one night) (Note: unusual form since "Nacht" is a feminine noun)

 

• with a very small number of adjectives, e.g.

sich einer Sache bewusst sein (to be aware of something)

sich einer Sache gewiss sein (to be certain of something)

 

• in some expressions, e.g.

meines Wissens (as far as I know)

ich bin anderer Meinung (I am of a different opinion)

guter/schlechter Laune sein (to be in a good/bad mood)

allen Ernstes (in all seriousness)

 

• with a very small number of verbs which are rarely used nowadays, e.g.

sich einer Sache erfreuen: Sie erfreute sich bester Gesundheit. (She enjoyed very good health.)

einer Sache bedürfen: Das bedurfte seiner Erlaubnis. (His permission was requested.)

einer Sache/einer Person gedenken: Wir gedenken der Opfer der Flutkatastrophe. (We remember the victims of the flood disaster.)