Immer wiederholen!German cases
German has four cases: Nominativ, Akkusativ, Dativ, and Genitiv. A case is a form a noun (and the article that goes with it) takes to show its role in the sentence: who's acting, who or what the action affects, who something is meant for. The tricky part isn't the concept itself — it's that German's rules for picking a case don't always match what English speakers expect, so they have to be learned word by word.
How the article declines across cases
| Case | Masculine | Feminine | Neuter | Plural |
|---|---|---|---|---|
| Nominativ | der | die | das | die |
| Akkusativ | den | die | das | die |
| Dativ | dem | der | dem | den |
| Genitiv | des | der | des | der |
How the indefinite article declines across cases
ein has no plural form — "a/an" can't logically be plural — so there are only
three genders here, no plural column.
| Case | Masculine | Feminine | Neuter |
|---|---|---|---|
| Nominativ | ein | eine | ein |
| Akkusativ | einen | eine | ein |
| Dativ | einem | einer | einem |
| Genitiv | eines | einer | eines |
What each case does
Nominativ is the subject's case: who or what performs the action
(Der Hund schläft. — the dog is sleeping). Akkusativ is the
direct object's case: who or what the action affects (Ich sehe den Hund. — I
see the dog). Dativ is the indirect object's case: who or what the action
is directed at (Ich gebe dem Hund das Futter. — I give the dog the food).
Genitiv is the case of possession: whose (das Futter des
Hundes — the dog's food).
In a sentence with two objects, the recipient of the action usually takes Dativ, and the
thing being given takes Akkusativ: Ich gebe dir (Dativ) das Buch (Akkusativ).
Why the case isn't always predictable from meaning
That general rule doesn't always hold. For many German verbs and prepositions, the case of
the object is simply fixed by convention — this is called government (Rektion) — and
doesn't follow logically from meaning. helfen (to help) takes Dativ, even
though logic suggests Akkusativ; prepositions like für, mit, and
durch also always take one specific case regardless of context, and for some
prepositions (an, auf, in...) the case depends on
whether the sentence describes motion or location. These have to be memorized individually
— see "Prepositions and cases" and
"Verbs with Dativ (no preposition)" for more.
Practice
To make sure it sticks, try a few exercises on the cases verbs and prepositions take.