What are the nominative, accusative and dative cases and when should I use them?

Using the cases correctly is vital, as different cases will change which word you use for 'the' (there are 12 words for 'the' in German!), and will also have an impact on the endings of adjectives and indefinite articles. It's also quite confusing for beginners as this grammar concept doesn't really exist in English. Nominative- subject of a sentence, the thing doing an action or being described eg. ich, du, sie, es. Example sentence: Er ist meinen Bruder Accusative- direct object, also used after FUDGEBOW prepositions, eg. ihn, ihr example sentence: Ich mag ihn nicht. Dative- indirect object, indirect object being the person or thing that an action is meant to benefit. Also used after aus, bei, mit, nach, seit, von, zu, hinter, vor and an. Example sentence: Der Lehrer gibt einer Schülerin ein Beispiel