German Adjective Endings (Adjektivdeklination) Without the Panic

Adjective endings have a reputation as the single most punishing part of German grammar, and the reputation is partly earned: there are technically three separate declension patterns, four cases, three genders, and a plural, which multiplies out to dozens of theoretical combinations. The good news: the endings aren't random, there are only five actual endings in play (-e, -en, -er, -es, -em), and one simple principle explains most of the pattern before you ever open a table.

The one idea that unlocks the whole system

German adjective endings exist to mark case, gender, and number exactly once per noun phrase: not redundantly on every word. If the article in front of the adjective already makes the case/gender/number obvious (like der, die, das, den, dem), the adjective can get away with a weak, minimal ending. If there's no article at all doing that job, the adjective itself has to carry the full information, so it gets a strong ending that mimics what the missing article would have shown. This single trade-off: "who's doing the signaling, the article or the adjective?": is the logic behind all three tables below.

Weak declension (after der/die/das, dieser, jeder, welcher...)

The definite article already signals everything, so the adjective is "weak": almost always -e or -en.

	Masc.	Fem.	Neut.	Plural
Nominative	der gute Mann	die gute Frau	das gute Kind	die guten Leute
Accusative	den guten Mann	die gute Frau	das gute Kind	die guten Leute
Dative	dem guten Mann	der guten Frau	dem guten Kind	den guten Leuten
Genitive	des guten Mannes	der guten Frau	des guten Kindes	der guten Leute

Notice: out of 16 slots, only four are -e (all nominative, plus feminine and neuter accusative): everything else is -en. That's the whole weak table in one sentence: "-e in the four slots that are nominative-or-neutral, -en everywhere else."

Mixed declension (after ein, kein, mein, dein, sein...)

The indefinite article signals case in most slots, but, critically, ein itself has no ending in masculine nominative and neuter nominative/accusative, so the adjective has to step in and cover for it there. Everywhere else, it behaves exactly like the weak table.

	Masc.	Fem.	Neut.	Plural
Nominative	ein guter Mann	eine gute Frau	ein gutes Kind	keine guten Leute
Accusative	einen guten Mann	eine gute Frau	ein gutes Kind	keine guten Leute
Dative	einem guten Mann	einer guten Frau	einem guten Kind	keinen guten Leuten
Genitive	eines guten Mannes	einer guten Frau	eines guten Kindes	keiner guten Leute

Only three cells differ from the weak table: masculine nominative (-er) and neuter nominative/accusative (-es): precisely the three slots where ein itself is ending-less and ambiguous. Everywhere ein already looks like der/die/das in shape, the adjective goes back to -en.

Strong declension (no article at all)

With no article present: after quantity words like viel, wenig, plain plural nouns, or numbers: the adjective is the only thing signaling case and gender, so it takes on endings that look almost exactly like the definite article's own endings.

	Masc.	Fem.	Neut.	Plural
Nominative	guter Kaffee	gute Suppe	gutes Brot	gute Ideen
Accusative	guten Kaffee	gute Suppe	gutes Brot	gute Ideen
Dative	gutem Kaffee	guter Suppe	gutem Brot	guten Ideen
Genitive	guten Kaffees	guter Suppe	guten Brotes	guter Ideen

Compare this row-by-row to der, die, das, den, dem, des and you'll see the adjective endings are nearly a direct copy of the article endings (with the genitive masculine/neuter softened to -en for pronunciation reasons). That's the shortcut: strong endings = "pretend the adjective is the missing article."

A practical way to actually learn this

1. Learn the weak table first: it's the smallest (only two endings total) and it's genuinely the most common pattern in daily speech, since der/die/das-type articles are everywhere.
2. Learn the three mixed-table exceptions as a standalone fact: "masculine nominative -er, neuter nom/acc -es, everything else same as weak." Don't relearn the whole table: just the delta.
3. For strong endings, don't memorize a fourth table: recognize it's just the definite article's endings transplanted onto the adjective. If you already know der/die/das declension cold, you already know 90% of strong adjective endings.
4. Drill with real nouns you use daily (Kaffee, Wetter, Auto, Freund) rather than abstract tables: the ending becomes part of the phrase's rhythm, not a rule you consciously apply.

Common mistakes

• Applying strong endings after ein/mein/dein out of habit, forgetting that ein in most slots already signals the case (mixed declension, not strong).
• Using -e everywhere as a safe default: it's correct surprisingly often after der/die/das-type words, which reinforces the habit, but it fails immediately in the dative and genitive.
• Forgetting adjectives after alle, beide, diese (plural, definite-like) follow the weak plural pattern (-en), while adjectives after viele, wenige, einige (indefinite quantity) follow the strong plural pattern (-e/-er).

Practice adjective endings inside full sentences, not isolated tables, in our B1 and B2 courses, and test yourself with a mock exam.