Forming the plural
As you know, theer are different ways to form the plural in German. The most common is to add the endings -(e)n and -e. In some nouns, the vowels a, o and u then change into ä, ö and ü (especially in nouns with the plural ending -e ).
der Pilz - die Pilze, der Baum - die Bäume
the mushroom - the mushrooms, the tree - the trees
Abbreviations, foreign words, and nouns ending in a, i, o or u receive the ending -s in the plural
der App - die Apps, das Auto - die Autos
the app - the apps, the car - the cars
More ways of forming the plural
Many neuter and some masculine nouns from the plural with the ending -er. In these nouns, a, o and u then often becomes ä, ö and ü
der Wald - die Wälder, das Bild - die Bilder
the forest - the forests, the image - the images
Neuter and masculine nouns ending in -lein, -chen, -er, -en and -el don not have a plural ending but the vowels may change
das Mädchen - die Mädchen
the girl - the girls
der Garten - die Gärten
the garden - the gardens
Es gibt... + accusative
The German expression es gibt is a set expression which always remains in the third person singular
Es gibt einen schönen Wanderweg hier - Es gibt schöne Wanderwege hier
There is a beautiful hiking trail here - There are beautiful hiking trails here
As you may have already noticed, es gibt always requires accusative
Die Wanderer sagen, es gibt einen Bären im Wald!
The hikers say that there is a bear in the forest!
The accusative
As you already know, the use of the accusative depends on the verb or the preposition. Some verbs that require the accusative are haben or the (to have), sehen (to see), machen (to make) and essen (to eat)
Sie machen eine Pause und essen einen Apfel.
They are having a break and eating an apple
Siehst du die Wildschweine und den Hirsch da vorne?
Do you see the wild boars and the stag up ahead?
The following prepositions always require accusative: für, durch, gegen, ohne and um
Wir sind durch einen wunderschönen Wald gewendert
We wandered through a beautiful forest