| Nominative | Accusative | Dative | Genitive |
| No Article |
Protestbrief |
Protestbrief |
Protestbrief/Protestbriefe |
Protestbriefes/Protestbriefs |
| |
| Definite Article |
der Protestbrief |
den Protestbrief |
dem Protestbrief/Protestbriefe |
des Protestbriefes/Protestbriefs |
| |
| Indefinite Article |
ein Protestbrief |
einen Protestbrief |
einem Protestbrief/Protestbriefe |
eines Protestbriefes/Protestbriefs |
| |
Plural
No Article |
Protestbriefe |
Protestbriefe |
Protestbriefen |
Protestbriefe |
| |
Plural
Definite Article |
die Protestbriefe |
die Protestbriefe |
den Protestbriefen |
der Protestbriefe |
