That is why the concept of has become the holy grail for self-learners and intensive course students alike.
The Dativ Plural always adds an '-n' if it doesn't already have one. Memory Hook: Der, Die, Das – Den, Die, Das – Dem, Dem, Der – Des, Des, Der. 40 deutsche grammatik listen a1-c2 pdf
Viel Erfolg beim Deutschlernen!