Genitive endings

[warm reef]

In the genitive case when should i put an ending like en or es on the noun?

[tender tulip]

I found a little table that you might find useful

[harsh portal]

First off, feminine nouns don't take any endings in the genitive.

Only masculine and neutral nouns need an ending in the genitive singular:

• nouns following the strong declension take -s or -es;
• nouns following the weak declension (N-Deklination, all masculine) take -en
  ||(not only in the genitive singular, but in all the cases other than nominative singular)||

[harsh portal]

faq Genitiv