I think this website might be helpful for you. http://www.canoo.net/services/OnlineGrammar/Wort/Nomen/index.html?lang=en http://www.canoo.net/services/OnlineGrammar/Wort/Nomen/Kasus/index.html?lang=en Nominativ is the easiest. It's the subject of a sentence. Just take the words as they are from your dictionary. der Mann, die Frau, das Kind, ... Akkusativ and Dativ are refering to the verb. Ich - sehen - der Hund => Ich sehe den Hund. sehen + Akkusativ Dativ is used for the secondary object, even if you omit the main object. Ich - vergeben - du - deine Fehler Ich vergebe dir [Dativ] deine Fehler [Akkusativ]. jemandem [Dativ] etwas [Akkusativ] vergeben http://dict.leo.org is very useful as it shows you the cases. Genitiv is rarely used with verbs. Just with a handful. But it's always used for "whose" thing it is. You can compare it to Frensh. la balle du garçon => der Ball des Jungen "des Jungen" is Genitiv. Because it's "his ball". You must also be careful with adverbial phrases. in das Haus (into the house) -> Akkusativ im Haus (in the house) -> Dativ wegen des Mannes (because of the man) -> Genitiv