德文文法搞唔清

Each German noun have "die, der or das".

Like:

Der Land
Die Schule (School)
Das Buch (book)
Die Bergen (The Mountains, * notice plural)

All the pural nouns are "Die".

-Der Die Das Die is used in Subject

When use in accuative case, it use

-Den Die Das Die

In dative case,

-Dem Der Dem Den

So just use the chart

Subject RESE
Acusative NESE
Dative MRMN

ex.

Ich habe ein grosses (gross [big] + adjective ending for das noun, which is 'es' Bett in meinem Zimmer.
____

Zu, bei, von are Dative prepostion, all noun after those are Dative form.

Zu = to
Bei = by
Von = from

To School = zu der Stadt gehen [Stadt [city] is die in subject, der in Dative]
To make it shorter become => zur Stadt gehen

same apply to other preposition.