German Adjective Endings: Ein guter Kaffee or Der gute Kaffee?
German adjectives usually take endings when placed before a noun, but not when used after sein as descriptions: guter Kaffee, Der Kaffee ist gut. The ending depends on case, gender, number and the article already present. Begin with nominative examples, then contrast masculine accusative. Learn the phrase as a coordinated unit rather than choosing an adjective ending in isolation.
Published 29 September 2026 · Updated 13 October 2026
Der Kaffee ist gut is straightforward: The coffee is good. Move gut before Kaffee and it needs an ending: der gute Kaffee. Add ein instead of der and it becomes ein guter Kaffee. The adjective has to cooperate with its neighbours.
Two jobs, two forms
Construction
German
English
Description after sein
Der Kaffee ist gut.
The coffee is good.
Before noun with der
der gute Kaffee
the good coffee
Before noun with ein
ein guter Kaffee
a good coffee
Before noun without article
guter Kaffee
good coffee
An adjective used before a noun is called attributive. A describing adjective after sein is predicative. You can understand the distinction without remembering the labels, but it explains why gut is sometimes unchanged.
Start with nominative singular
With definite articles: der gute Kaffee, die gute Idee, das gute Buch. The adjective takes -e in these examples. With indefinite articles: ein guter Kaffee, eine gute Idee, ein gutes Buch. Masculine -er and neuter -es give information that the bare ein form does not show.
This information-sharing explanation is a helpful memory aid, not a complete algorithm for every cell. Feminine eine is followed by gute, and plural and case patterns add details. Check a reliable table when working beyond the starter examples.
The masculine accusative changes the pair
Ich trinke einen guten Kaffee — I’m drinking a good coffee. The noun is masculine and is the direct object of trinken, so the indefinite article becomes einen and the adjective guten. With the definite article: Ich trinke den guten Kaffee.
Feminine and neuter accusative keep the starter forms: Ich habe eine gute Idee — I have a good idea; Ich lese ein gutes Buch — I’m reading a good book. “Accusative makes every adjective -en” is therefore not the rule.
Plural and dative examples
Die guten Bücher means the good books. Without an article, gute Bücher means good books. In the dative: mit einem guten Buch — with a good book; mit den guten Büchern — with the good books. In the latter, the noun adds dative plural -n too.
Traditional grammar describes strong, weak and mixed adjective patterns. Strong endings commonly occur without an article; weak endings follow definite articles; mixed endings follow words such as ein. These labels describe coordinated sets of forms, not three kinds of meaning.
A practical decision order
Identify the case from the sentence first. Retrieve the noun’s gender and number. Check the article or article-like word. Then choose the adjective ending. If you begin by guessing -e or -en, you are choosing before you know the information that decides.
Complete Das Buch ist gut___, ein gut___ Buch and Ich trinke einen gut___ Kaffee. Answers: no ending after gut in the first; -es in the second; -en in the third. Practise these complete phrases before expanding to the full chart.