New students of the German language will note that German grammar follows a fairly strict set of rules, although like any language, very gradual changes have occurred over the past few centuries.
Changes seem to happen more quickly in the spoken language than in the written form. Formal rules actually will help the student learn the language more quickly. Languages that have a lot of exemptions to the rules can be much more confusing.
Genders in german grammar
German grammar utilizes three genders: the masculine, the feminine and neuter. German differs from English in that the gender of a noun and the sex of the thing described may be different.
An example is a neutral object, like a stone. It is known as "der Stein" in German, which is masculine.
And while words describing a man and a woman make total sense gender-wise, when dealing with "girl," which is das Mädchen or "young woman," which is das Fräulein, they are neutral. When dealing with some objects, the assigning of a gender seems random. For example, fork is feminine (die Gabel), knife is neutral (das Messer) and spoon is masculine (der Löffel).
For new students of the German language, it is easiest to just memorize the proper definite article along with the noun.
Cases – General
The German language utilizes four cases. Nominative refers to the subject. Accusative refers to a direct object. Dative refers to an indirect object and genitive refers to a possessive object. The case used for a particular noun will depend on the grammatical function the noun performs in the sentence.
The genitive case has been declining in the German language for hundreds of years. It is rarely used in spoken German, although it is still expected in properly written German. This case is used to indicate ownership or possession. For example, das Haus meiner Eltern (my parent's house) shows ownership. For masculine and neuter genders, the genitive adds –es, such as in "meines Hundes", while for the feminine or plural forms, an –er is used, like the previous example of meiner Eltern.
The dative case is used for indirect objects. Both the definite and indefinite articles in the masculine or neuter genders add –em to the article, such as in diesem or einem. For the feminine gender, -er is used, as in dieser or keiner.
For plural forms, -en is added to the articles, as in diesen or keinen.
Cases After Prepositions
Nouns that are used after a preposition have cases decided by the preposition. There are no prepositions that require the nominative case, but other cases will be used accordingly. For example, the preposition für (for) uses the accusative case, while the word mit (with) uses the dative. Wegen (because of) can use the genitive case in written language and the dative in spoken language.
Some prepositions can use either accusative or dative, depending on if the use implies position or direction. An example would be in der Küche (in the kitchen, which is dative) or in die Küche (into the kitchen, which is accusative).