The German language has got three noun genders (gender = Genus): Maskulinum (= masculine), Femininum (= feminine) and Neutrum (= neuter).
In its basic form (Nominativ) you can recognize the gender of a noun by its definite article: Maskulinum: „der“ (e.g. „der Mund“) / Femininum: „die“ (e.g. „die Nase“) / Neutrum: „das“ (e.g. „das Auge“).
Depending on the case, the articles (as well as other word types) can have different forms:
Nominative: der, die, das
Accusative: den, die, das
Dative: dem, der, dem
Genitive: des, der, des
A table containing the German nouns and articles in all their forms you can find HERE.
In the following exercises there is always a noun highlighted. Make a click onto the gender of the highlighted noun.
Have fun!