Adjective Declension (Indefinite Articles) in German

Overview

When an adjective comes between an indefinite article (ein, eine, ein) and a noun, it follows the mixed declension pattern. This pattern is called "mixed" because it blends elements of the weak declension (used after definite articles) and the strong declension (used without articles). At the A2 level, this is the second adjective declension pattern to learn, and it is extremely common since you use indefinite articles all the time.

The core principle is that someone needs to show the gender and case of the noun. Since indefinite articles do not always do this clearly — "ein" can be masculine nominative or neuter nominative or neuter accusative — the adjective steps in to carry that information with a stronger ending. Where the article is ambiguous, the adjective ending becomes more distinctive.

This means you will see endings like -er (masculine nominative), -es (neuter nominative/accusative), and -e (feminine nominative/accusative) — endings that look like the definite article endings themselves.

How It Works

Mixed Adjective Endings (After Indefinite Articles)

Case	Masculine	Feminine	Neuter	Plural (keine)
Nominative	-er	-e	-es	-en
Accusative	-en	-e	-es	-en
Dative	-en	-en	-en	-en

Key observation: The dative is always -en, and the plural is always -en. The distinctive endings appear in the nominative and accusative singular, where the indefinite article does not fully reveal the gender.

Compare with the definite article pattern

Case	After "der" (weak)	After "ein" (mixed)	Difference
Nom. masc.	der große Mann	ein großer Mann	-er shows masculine
Nom. neut.	das große Kind	ein großes Kind	-es shows neuter
Nom. fem.	die große Frau	eine große Frau	Same: -e
Acc. masc.	den großen Mann	einen großen Mann	Same: -en

This pattern also applies after:

• kein (no/not a): kein großer Mann
• Possessive articles: mein, dein, sein, ihr, unser, euer, ihr, Ihr

These are called "ein-words" because they behave exactly like ein in their endings.

Examples in Context

German	English	Note
Ein großer Mann kommt.	A tall man is coming.	Masculine nominative: -er
Ich habe eine neue Tasche.	I have a new bag.	Feminine accusative: -e
Mit einem alten Freund.	With an old friend.	Masculine dative: -en
Ein kleines Kind spielt dort.	A small child is playing there.	Neuter nominative: -es
Ich suche einen guten Arzt.	I'm looking for a good doctor.	Masculine accusative: -en
Sie hat ein schönes Kleid.	She has a beautiful dress.	Neuter accusative: -es
Er trinkt keinen heißen Kaffee.	He doesn't drink hot coffee.	Masculine accusative with kein: -en
Das ist meine neue Wohnung.	That is my new apartment.	Feminine nominative with possessive: -e
Wir haben keine alten Bücher.	We don't have any old books.	Plural accusative with kein: -en
In einer großen Stadt.	In a big city.	Feminine dative: -en

Common Mistakes

Using weak endings after ein

• Wrong: Ein große Mann kommt.
• Right: Ein großer Mann kommt.
• Why: After "ein" in the masculine nominative, the adjective must show the gender with -er. The weak ending -e does not provide enough information.

Confusing neuter nominative and accusative with masculine

• Wrong: Ein großer Kind spielt.
• Right: Ein großes Kind spielt.
• Why: "Kind" is neuter, so the adjective needs -es in the nominative, not -er (which signals masculine).

Applying mixed endings after definite articles

• Wrong: Der großer Mann.
• Right: Der große Mann.
• Why: After definite articles (der/die/das), use weak endings (-e/-en). The mixed endings (-er/-es) are only for ein-words.

Usage Notes

The mixed declension is probably the pattern you will use most often in everyday German, since indefinite articles and possessives (mein, dein, etc.) are extremely common. Sentences like "Das ist ein guter Film" (That's a good film), "Ich habe eine tolle Idee" (I have a great idea), and "Er ist mein bester Freund" (He is my best friend) all use this pattern.

The key mental shortcut: in the three positions where "ein" is ambiguous (masculine nominative, neuter nominative, neuter accusative), the adjective takes on the job of showing gender. In all other positions, the article or the -en ending handles it.

Practice Tips

1. Compare the same noun phrase with a definite and indefinite article side by side: "der große Mann" vs. "ein großer Mann," "das kleine Kind" vs. "ein kleines Kind." This highlights where the endings differ and why.
2. Practice with possessives, since they follow the same pattern: "mein neuer Job," "deine alte Schule," "sein großes Haus." This multiplies your practice opportunities.
3. Focus first on getting the nominative endings right (-er, -e, -es), since these are the distinctive ones. The dative is always -en, and the accusative masculine is always -en — those are easy.

Related Concepts

• Adjective Declension (Definite Articles) — the weak declension pattern to compare with
• Adjective Declension without Articles — the strong declension when no article is present