The exercise itself is in German; the explanation pages it links to are in Turkish.
Adjektivdeklination (after the definite article: -e / -en)
After the definite article (weak declension) the adjective takes only two endings: -e → Nominativ singular + Akkusativ feminine/neuter; -en → everywhere else (masculine Akk., all of the Dativ, all of the plural). All exercise content is in German.
Recognise: match the article type and case with the example that fits. All three declension types together.
Matched: 0 / 10Quick answer
What is in the "Adjektivdeklination" exercise?
The "Adjektivdeklination" exercise is at level B1 and has 5 steps with 50 questions in total: 10 matching items, 30 multiple-choice questions and 10 gap-fill items.
The steps in order: Match · Definite art. · ein/no article · Richtig/Falsch · Write.
You get instant feedback after every answer; the exercise runs in your browser, is free and needs no sign-up or installation.
Where can I study "Adjektivdeklination"?
The explanation for this exercise is on the page Adjektivdeklination – German Adjective Endings (A2/B1) (in Turkish). Read the rule there, then reinforce it with the 50 questions on this page.