The german language has four different cases. Each case has particular role or function in the sentence. Normaly you see that a noun is a subject when it comes before the verb. If it is an object, it comes after the verb. In German, these different roles are signalled by the case and are shown in the endings. To kow the case in a sentence ist improtant, beacuse the case dictates the ending of definite articles (der, die, das), indefinite articles (ein, eine, ein) and adjectives linked with nouns.
The nominative case (der Nominativ):
The nominative case in a sentence is used when the noun is the subject of the sentence,. That means the subject ist the agent of what is happening. It is the answer (in a sentence) to the question „whoor waht is doing the action?
The genitive case (der Genitive):
The genitive caes is used in a sentence to show the relationship between two nouns. It indicates that one thing belongs to the other.
The dative case (der Dativ):
In accusative case forms the direct object. Many verbs in the german language can take a second object, the so called indirect object (indirektes Objekt). The indirect object is the answer in a sentence to the question to whom or what, or for whom is the action done.
The accusative case (der Akkusativ):
The noun in the accusative is the so called direct object. That means this noun is the receiver of the action in the sentence. The direct object is the answer to the question who or what is affected by
But this is not the whole truth. The case of a noun in a sentence is not only determined by its function in the sentence. The case can be terminated by the used verb and the preposition.This is the reason why its is so important to learn which verbs take the dative, and which prepositions take a special case. Preposition in German require a certain case. For example the preposition equires the dative case, then the object in the German sentence must be in the dative even if it have the function of a direct object. Example: „For my friend“ is the indirect object, but the german translation „für meinen Freund“ is in the accusative case because the preposition „für“ requires the accusative.
Notes to different cases in German:
German: Er ist ein netter Mann (the ending -er of netter indicates the monainative cas)
English: He is a nice man.