Adjective Endings after ein/kein/Possessives

1.Endings after ein, kein, and possessives

After ein, kein, and possessive determiners, an adjective before a noun takes an ending. This group includes ein / eine, kein / keine, and also mein, dein, sein, ihr, unser, euer, Ihr and their forms.

This system is often called the mixed adjective declension, because grammatical information is shared between the determiner and the adjective.

2.Main idea

If a determiner like ein does not clearly show important grammatical information, the adjective takes the stronger ending.

In der the ending -er is already visible, so the adjective only takes -e. In Nominative masculine ein has no visible ending, so the adjective shows the information: gut + -er → guter. The same is true in the neuter: ein does not clearly mark Neutrum Nominative, so the adjective takes -es.

3.Which words use this model

All of these words follow the same basic declension system.

4.Main table

Adjective endings:

5.Nominative: -er, -es, -e

In Nominative masculine ein has no visible ending (ein Mann, mein Bruder, kein Termin), so the adjective takes strong -er. In the neuter the same applies: the adjective takes -es. In the feminine the determiner already has a visible ending (eine, meine, keine), so the adjective takes -e.

6.Accusative masculine: -en

In Accusative masculine the ein-word takes -en (einen, meinen, keinen, deinen), and the adjective also takes -en. This is a very important A2 pattern.

7.Accusative feminine and neuter

Feminine and neuter Accusative look almost the same as Nominative: feminine → -e, neuter → -es.

8.Dative: almost always -en

After ein-words the adjective in the Dative always takes -en.

9.Genitive: also -en

In the Genitive the adjective after ein-words also takes -en. At A2 the Genitive is less central than Nominative, Accusative, and Dative, but the adjective pattern is simple. Masculine and neuter nouns often also take -s or -es.

10.Plural: ein has none, but kein and possessives do

The indefinite article ein has no plural form: you cannot say eine Freunde. But kein and possessive determiners have plural forms (keine, meine, deine, seine, ihre, unsere, eure, Ihre). After them the adjective usually takes -en. In Dative plural the noun often also takes -n.

11.kein like ein

kein is declined like ein, but adds a negative meaning. When choosing the adjective ending, you can treat kein as an ordinary ein-word.

12.Possessives like ein

Possessive determiners follow the same model. Who the owner is does not change the adjective-ending system.

13.euer → eure

euer changes shape when an ending is added: the second e often drops (euer + e → eure, euer + en → euren, euer + er → eurer).

14.Comparison with the definite article

After der / die / das the article clearly shows grammatical information. After ein that marking is missing in some positions — then the adjective takes the stronger endings -er and -es.

15.Short practical rule

First learn three visible forms: ein guter Mann, ein gutes Kind, eine gute Frau. Then Accusative masculine: einen guten Mann. Almost everywhere else: -en. This shortcut does not replace the full table, but it reduces the load. Especially important are -er, -es, -e, -en.

16.How to determine the ending: four steps

1. Which case? Nominative, Accusative, Dative, or Genitive?
2. Which gender or plural?
3. Which ein-word stands before the adjective?
4. Does the ein-word show grammatical information clearly enough? If not, the adjective takes the stronger ending.

Example: Nominative + masculine + mein → mein has no visible case ending → mein neuer Job.

17.Full sentences: Nominative, Accusative, Dative

In Nominative the gender differences are especially clear. In Accusative the contrast ein neuer Computer / einen neuen Computer is especially important. In Dative you can almost always rely on -en.

18.After prepositions: Dative and Accusative

The preposition helps determine the case. First identify the case, then choose the adjective ending.

Common with Dative: mit, bei, von, zu, aus, nach, seit. Common with Accusative: für, ohne, durch, gegen, um.

19.Two-way prepositions

With two-way prepositions first decide: Wo? → Dative, Wohin? → Accusative. The adjective ending depends on the case the preposition requires in that meaning.

20.Several adjectives

If several adjectives stand before one noun, they usually take the same ending. The ein-word sets the declension model for all attributive adjectives in that group.

21.After sein, werden, bleiben: no ending

The endings in this article belong to attributive adjectives — adjectives directly before a noun. After sein, werden, bleiben there is no declension ending.

22.Zero article: another system

Without an article before the adjective a different model applies, not the same one as after ein / kein / a possessive. This article deliberately covers: ein-word + adjective + noun — not adjective + noun with no article.

23.Everyday collocations

Such collocations are very common in everyday A2 German.

24.One ending ≠ one case

The adjective ending is part of the whole gender-and-case system. -en appears in many positions, so you cannot think that -en = Dative.

First identify case and gender, then look at the whole noun phrase.

25.The noun phrase as a whole

Instead of looking only at the adjective, it is more useful to read the whole group. There are three levels: possessive determiner, adjective, noun. All three parts can carry grammatical information. This is an important A1→A2 shift: treat not single words, but the phrase as a system.

26.The same noun through the cases

With ein neuer Tisch / mein neuer Computer and with eine neue Wohnung the changes are especially clear.

27.Common mistakes

28.Short algorithm

If you need to build a group like mein … neu… Computer:

1. Identify the case — e.g. object → Accusative.
2. Identify the gender — der Computer → masculine.
3. Decline the possessive — masculine Accusative → meinen.
4. Choose the adjective ending — after meinen → -en.

Result: meinen neuen Computer. That sequence is more reliable than guessing.

29.Compact reference table

Most visible forms: Nominative masculine → -er; Nominative/Accusative feminine → -e; Nominative/Accusative neuter → -es; almost everywhere else → -en.