German adjective endings
Build German adjective phrases and practice strong, weak and mixed declension. Compare all four cases with clear explanations and mistake review.
Select case, noun and determiner in the phrase helper.
Compare the ending across all four cases.
Practice contextual sentences and review the reason for each ending.
ein gutes Buch
Ending: -es · Mixed declension · neuter · nominative
Where ein has no ending, the adjective carries gender: ein guter Mann, ein gutes Buch. After inflected forms such as einem, the adjective uses -en.
| Case | Your phrase |
|---|---|
| nominative | ein gutes Buch |
| accusative | ein gutes Buch |
| dative | einem guten Buch |
| genitive | eines guten Buches |
These are grammatical phrase forms; not every adjective–noun combination is equally natural. The helper uses adjectives with regular stems. Adjectives after sein stay uninflected: Das Buch ist gut.
Make sense of what you’re practicing
Three questions determine the ending
Identify the case first, then gender and number, then the word before the adjective. Der-words normally lead to weak endings, ein-words to mixed endings, and no determiner to strong endings. The helper keeps these decisions visible so you can understand the form rather than memorize a disconnected table.
Weak, mixed and strong adjective declension
With der, die or das, most information is already in the article: der gute Mann, den guten Mann. Ein lacks a visible ending in some positions, so the adjective supplies it: ein guter Mann, ein gutes Kind. With no article, the adjective carries more information: guter Wein, mit gutem Wein.
The genitive exception learners often miss
Strong genitive masculine and neuter use -en: trotz starken Regens, wegen schlechten Wetters. The noun has -(e)s. Genitive feminine and plural without a determiner use -er, as in der Duft frischer Blumen. Dative plural uses -en and often adds -n to the noun as well.
When adjectives do not take an ending
Predicative adjectives after sein, werden or bleiben are normally uninflected: Das Buch ist gut. The adjective is inflected when it comes before a noun: ein gutes Buch. This tool practices attributive adjectives and regular adjective stems.