Adjective endings in simple contexts (nominative and accusative with definite and indefinite articles)

What does this mean?

Adjective endings in German are small changes at the end of an adjective (like -e, -en, -er, -es) that agree with the noun they describe. In this article we look only at simple situations: adjectives directly before a noun (attributive adjectives) in the nominative (subject) and accusative (direct object) cases, when the noun has either a definite article (der/die/das/die) or an indefinite article (ein/eine — or equivalent words like kein, mein).

Important point: Only attributive adjectives (before the noun) take endings. Predicate adjectives after verbs like sein (to be) do not take these endings. Compare:
- Attributive: Der groe0e Hund schläft. (The big dog sleeps.)
- Predicative: Der Hund ist groe0. (The dog is big.)

When do I use nominative vs accusative?

Nominative = the subject (who/what does something). Example: Der junge Mann liest. (The young man reads.)
Accusative = the direct object (who/what is affected). Example: Ich sehe den jungen Mann. (I see the young man.)

Why do endings change with the article?

German uses three main "patterns" for adjective endings (strong, weak, mixed). For our simple cases:

After a definite article (der/die/das/die), the article already shows gender, number and case, so the adjective usually uses the weak pattern.
After an indefinite article (ein/eine, kein, mein, dein...), the article does not always show all information, so the adjective fills in some of the missing information (mixed pattern).

Which endings follow the definite article (der/die/das)?

Rule in short: With der/die/das (and similar words like dieser, jener, jeder), use the weak endings. In nominative singular the adjective usually ends in -e; in many other cells it is -en.

Nominative (definite)
- Masculine: der groe8e Mann (der groe8e Mann liest die Zeitung.) — adjective ending: -e
- Feminine: die rote Blume (die rote Blume ist schf6n.) — ending: -e
- Neuter: das kleine Kind (das kleine Kind spielt.) — ending: -e
- Plural: die neuen Autos (die neuen Autos stehen dort.) — ending: -en

Accusative (definite)
- Masculine: den groe8en Hund (Ich sehe den groe8en Hund.) — ending: -en
- Feminine: die rote Blume (Ich pflfccke die rote Blume.) — ending: -e
- Neuter: das kleine Kind (Die Frau sieht das kleine Kind.) — ending: -e
- Plural: die neuen Autos (Wir reparieren die neuen Autos.) — ending: -en

Which endings follow the indefinite article (ein/eine, kein, mein...)?

Rule in short: With ein/kein/possessives (mein, dein...) use the mixed pattern. Because ein does not always show gender or case, the adjective must sometimes show it: masculine nominative -> -er, neuter nominative/accusative -> -es, and many other forms -> -en.

Nominative (indefinite)
- Masculine: ein guter Mann (Ein guter Mann hilft.) — adjective ending: -er
- Feminine: eine rote Blume (Eine rote Blume steht im Fenster.) — ending: -e
- Neuter: ein gutes Buch (Ein gutes Buch liegt auf dem Tisch.) — ending: -es
- Plural: (no "ein" plural) use keine/meine/etc.: keine guten Gründe / meine neuen Schuhe — ending: -en

Accusative (indefinite)
- Masculine: einen guten Mann (Ich kenne einen guten Mann.) — ending: -en
- Feminine: eine rote Blume (Ich kaufe eine rote Blume.) — ending: -e
- Neuter: ein gutes Buch (Sie liest ein gutes Buch.) — ending: -es
- Plural: keine guten Gründe / meine neuen Schuhe — ending: -en

Comprehensive examples (every combination)

Below are clear examples for nominative and accusative with definite and indefinite articles, for all genders and plural.

Definite article (der/die/das) — Nominative

Masculine: Der kleine Mann wartet. (The small man is waiting.)
Feminine: Die rote Lampe leuchtet. (The red lamp is shining.)
Neuter: Das neue Fahrrad ist teuer. (The new bicycle is expensive.)
Plural: Die alten Häuser stehen noch. (The old houses are still standing.)

Definite article (der/die/das) — Accusative

Masculine: Ich sehe den kleinen Mann. (I see the small man.)
Feminine: Er kauft die rote Lampe. (He buys the red lamp.)
Neuter: Wir benutzen das neue Fahrrad. (We use the new bicycle.)
Plural: Sie reparieren die alten Häuser. (They repair the old houses.)

Indefinite article (ein/eine/kein/mein...) — Nominative

Masculine: Ein netter Nachbar hilft uns. (A nice neighbor helps us.)
Feminine: Eine kleine Katze schläft. (A small cat is sleeping.)
Neuter: Ein warmes Getränk schmeckt gut. (A warm drink tastes good.)
Plural: Keine alten Freunde sind gekommen. / Meine neuen Freunde kommen bald. (No old friends came. / My new friends will come soon.)

Indefinite article (ein/eine/kein/mein...) — Accusative

Masculine: Ich treffe einen netten Nachbarn. (I meet a nice neighbor.)
Feminine: Sie nimmt eine kleine Katze mit. (She takes a small cat with her.)
Neuter: Er bestellt ein warmes Getränk. (He orders a warm drink.)
Plural: Wir haben keine alten Freunde eingeladen. / Ich sehe meine neuen Freunde. (We invited no old friends. / I see my new friends.)

Common mistakes and how to avoid them

Forgetting that only attributive adjectives take endings. Wrong: Der Mann ist groe8e. Correct: Der Mann ist groe8 (predicate has no ending). For attributive: Der groe8e Mann.
Using the definite pattern after ein: Wrong: ein groß Mann. Correct: ein groe8er Mann.
Mixing up masculine accusative: Many learners forget den + -en. Correct: Ich sehe den groe8en Hund (not "den groe8e Hund").
Forgetting -es for neuter with ein: Wrong: ein gut Buch. Correct: ein gutes Buch.

Tips to remember quickly:
- If the article clearly shows gender and case (der/die/das), the adjective usually takes the weak ending: nominative singular -> -e, otherwise -> -en (for these simple cells).
- If the article does not show gender (ein, mein for masc nom; and plural often lacks "ein"), the adjective usually uses mixed endings: masc nom = -er, neuter nom/acc = -es, masculine acc = -en, feminine = -e.
- Learn a few model phrases and apply them: der groe8e Mann (weak), ein groe8er Mann (mixed), das groe8e Kind (weak), ein groe8es Kind (mixed).

Quick reference: endings (nominative and accusative)

Definite article (der/die/das/die) — weak declension:
Nominative: masc -e, fem -e, neut -e, pl -en
Accusative: masc -en, fem -e, neut -e, pl -en

- Indefinite article (ein/eine, kein, mein...) — mixed declension:
- Nominative: masc -er, fem -e, neut -es, pl -en
- Accusative: masc -en, fem -e, neut -es, pl -en

Glossary

Attributive adjective: an adjective placed before a noun and therefore declined (e.g., ein groe8er Hund).
Predicative adjective: an adjective after a verb like sein; it does not take those endings (e.g., Der Hund ist groe8).
Nominative: the subject case (who/what does something).
Accusative: the direct object case (who/what is affected by the action).
Definite article: der/die/das (the).
Indefinite article: ein/eine (a/an). Also includes words like kein (no) and possessives like mein (my).
Weak/mixed/strong declension: technical names for the adjective patterns. For simple learning, focus on the weak (after der/die/das) and mixed (after ein/mein).

Summary: the simplest learning path

1) First, know whether the adjective is before the noun (it needs an ending) or after a verb (no ending). 2) If the noun has a definite article (der/die/das/die), use the weak endings: nominative singular -> -e; accusative masculine and plurals -> -en. 3) If the noun has an indefinite article (ein/eine) or a possessive (mein/dein) use the mixed endings: remember

masc nominative = -er,
neuter nominative/accusative = -es,
feminine = -e,
masculine accusative and plural = -en.

Practice reading and noticing endings in short sentences; after a few dozen examples these patterns become automatic.