When and how are German adjectives declined?

In their declension, adjectives follow the respective antecedent (i.e., the noun they refer to) as long as they are placed before it. They can be inflected or, in particular, declined in three different ways. In detail, German grammar distinguishes between the following possibilities:

1. The strong declension …
   • … is used when the adjective precedes the noun without a determiner:
     • „Kaltes Wasser kann im Sommer sehr erfrischend sein.“ (Cold water can be very refreshing in summer.)
     • „Steile Berge können einem im Winter sehr zu schaffen machen.“ (Steep mountains can be very tiring in winter.)
2. The weak declension …
   • … applies when an additional determiner such as ‘der, dieser, jeder, mancher, welcher, derselbe, jener’ appears before the adjective and the subsequent noun:
     • „Der große Baum steht schon sehr lange im Garten.“ (The big tree has been in the garden for a very long time.)
     • „Manchem neuen Besucher gefällt die Ausstellung leider nicht.“ (Unfortunately, some new visitors don’t like the exhibition.)
3. The mixed declension …
   • … takes place when another type of determiner comes before the adjective and the noun following it. These can be ‘ein, kein, mein, dein, sein, ihr, euer, unser, irgendein’:
     • „Mein altes Fahrrad ging gestern kaputt.“ (My old bike broke down yesterday.)
     • „Irgendein ruhiges Plätzchen wäre jetzt schön.“ (Some quiet place would be nice now.)

What type of adjectives cannot be declined?

Important to note: Besides the majority of declinable adjectives, some exist that cannot be declined. These usually originate in other languages or are adjectives that represent colours. Compare:

• Many adjectives – but not all – that express colours, for example, ‘oliv, beige, lila, orange, rosa’ (olive, beige, purple, orange, pink), are indeclinable. Nevertheless, in colloquial language, they are often declined. For a better style, it is possible to add the ending ‘-farben’ alternatively.
  • Examples of colours that are not declined:
    • „Deine lila Jacke sieht super aus.“ (Your purple jacket looks great.)
      • not: „… lilane Jacke …“
      • but possible is: „… lilafarbene Jacke …“
    • „Meine Schwester hat sich einen oliv Schal gekauft.“ (My sister has bought an olive scarf.)
      • not: „… oliven Schal gekauft.“
      • but possible is: „… olivfarbenen Schal gekauft.“
  • But declinable are, for example:
    • „Den grünen Busch sollten wir noch nicht stutzen.“ (We shouldn’t trim the green bush yet.)
    • „Er schreibt immer mit roter Tinte.“ (He always writes in red ink.)
• Some examples of indeclinable foreign language adjectives:
  • „Dies würde extra Kosten verursachen.“ (This would incur extra costs.)
  • „Du hattest mal wieder eine super Idee.“ (Once again, you’ve had a brilliant idea.)

Further explanations referring to the ‘Declension of adjectives’

The following explanations are related to the topic ‘Declension of adjectives in German grammar’ and could also be interesting:

• Declension in grammar
• Nouns in German grammar
• Determiners of the noun