Rules and usage
German adjectives change their endings depending on the gender, number, and case of the noun they describe, as well as the article or determiner that precedes them. This system is called Adjektivdeklination, and while it appears complex, it follows predictable patterns once you understand the three main declination types: with a definite article, with an indefinite article, and without an article.
When adjectives need to change
Adjectives must decline whenever they come before a noun in the attributive position. Das große Haus is different from Der Mann ist groß because in the first example the adjective "große" comes before the noun and must show agreement, while in the second example "groß" is a predicate adjective and does not change. You decline an adjective even if it feels awkward or unnecessary in English—German requires this agreement to indicate case, gender, and number clearly.
✅ Positive sentence examples
| German | English |
|---|
| Der neue Lehrer kommt aus Berlin. | The new teacher comes from Berlin. |
| Ich kaufe einen blauen Stift. | I buy a blue pen. |
⛔ Negative sentence examples
| German | English |
|---|
| Der intelligente Schüler ist nicht faul. | The intelligent student is not lazy. |
| Ich mag diesen teuren Kaffee nicht. | I don't like this expensive coffee. |
❓ Question sentence examples
| German | English |
|---|
| Ist dieser alte Mann dein Opa? | Is this old man your grandfather? |
| Magst du die süße Schokolade? | Do you like the sweet chocolate? |