In German, when an adjective is used after sein the root of the adjective is used:

Der Hund ist blau.
The dog is blue.

However, when an adjective precedes a noun, it changes based on the gender, plurality and case of the noun it modifies, as well as whether it is being use in a definite (“the”), indefinite (“a”) or non-article context.

In this lesson will will go over how adjectives change in the nominative case. Please see the Accusative Adjectives and Dative/Genitive Adjectives lessons for those cases.

A noun is said to be in the definite context when it preceded by der, dar, die, etc. as well as with the demonstratives dieser, jeder, jener, etc. For singular nouns of all gender in this context a ~e ending is added:

der blaue Hund
The blue dog

die blaue Katze
the blue cat

das blaue Eichhörnchen
the blue squirrel

And when the noun is plural ~en is added regardless of gender:

Die blauen Hunde
The blue dogs

Die blauen Katzen
The blue cats


When the noun is in the indefinite context, that is when it is used after ~ein or ~eine words like ein, einen, keine, etc. it can have four different endings. It uses an -er ending if the noun is masculine:

ein blauer Hund
a blue dog

if the noun is neutral, a ~es ending:

ein blaues Eichhörnchen
a blue squirrel

If it is feminine, a ~e ending:

eine blaue Katze
a blue cat

And, if the noun is plural in the indefinite context it gets an ~en ending regardless of gender:

meine blauen Hunden
my blue dogs

meine blauen Katzen
my blue cats


When the noun and adjective are used on their own without an article context, the adjective changes in the same as in the indefinite (~ein) context except that all plural nouns use the feminine ~e ending:

Blauer Hund
Blue Dog

Blaues Eichhörnchen
Blue Squirrel

Blaue Katze
Blue Cat

Blaue Hunden
Blue Dogs