Questions & Answers about Welches Buch liest du heute?
Why is it welches Buch and not welche Buch or welcher Buch?
Welches has to match Buch in gender, number, and case.
- Buch is a neuter noun in German (das Buch).
- In this sentence, Buch is singular and in the accusative case (it’s the direct object of lesen).
- The interrogative welch- declines like an adjective. The correct form for neuter, singular, accusative is welches.
So:
- welcher = masculine (Nom./Dat. sg.)
- welche = feminine (Nom./Akk. sg.) or plural
- welches = neuter (Nom./Akk. sg.)
Because Buch is neuter, you must say welches Buch.
How do I know that Buch is in the accusative case here?
The verb lesen (to read) takes a direct object — the thing that is being read.
- The subject (the person doing the action) is du.
- The object (the thing being read) is Buch.
In German, a direct object is usually in the accusative case. So Buch is accusative here. Since Buch is neuter, nominative and accusative look the same (das Buch / ein Buch / welches Buch), so the case is shown more by the role in the sentence than by a changed ending on Buch itself.