Alle alten Termine müssen im Kalender durchgestrichen werden.

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Breakdown of Alle alten Termine müssen im Kalender durchgestrichen werden.

• dem: the; (masculine or neuter, dative)
• alt: old
• müssen: must

Questions & Answers about Alle alten Termine müssen im Kalender durchgestrichen werden.

Why is it Alle alten Termine and not Alle alte Termine?

Because of German adjective endings in the plural.

• Alle behaves like a "der-word" (like die, diese, jene, solche, welche, manche).
• After such words, adjectives take the weak declension, which in the plural is always -en, regardless of case.

So:

• alle alten Termine = all old appointments
  
  • alle = determiner (like "all")
  • alten = adjective with -en ending (weak declension)
  • Termine = plural noun

You cannot say alle alte Termine, because alte would be the strong ending; that is used without a der-word (e.g. alte Termine on its own, or after viele, wenige in some patterns).

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What case is Termine in here, and why?