Questions & Answers about Unsere schönen Pferde sind schnell.
Why does schönen have an -en ending?
It describes a plural noun (Pferde) and comes after a possessive word (Unsere). Whenever an adjective describes a plural noun and follows a possessive word (like unsere or meine), a negative word (keine), or a definite article (die), it always gets the -en ending.
Why doesn't schnell get an ending too, since it also describes the horses?
Adjectives in German only get endings when they sit directly in front of the noun they describe (like schönen Pferde). Because schnell comes after the verb (sind), it is a predicate adjective and stays in its basic dictionary form.
Why is the first word Unsere instead of just Unser?
The possessive word unser (our) needs to match the noun it belongs to. Since Pferde is plural and acts as the subject (nominative case) of this sentence, unser takes the plural -e ending to become Unsere.