Breakdown of Mit welcher Bürste putzen Sie den Napf?
mit
with
putzen
to clean
welcher
which (welcher, welche, welches, welchen, welchem...)
die Bürste
the brush
Questions & Answers about Mit welcher Bürste putzen Sie den Napf?
Why is it welcher instead of welche?
The word welch- (which) takes the same endings as definite articles (der, die, das). Here, it follows the preposition mit (with), which always forces the dative case. Since Bürste (brush) is a feminine noun, it takes the feminine dative ending -er, making it welcher.
Why does the sentence start with Mit welcher Bürste?
In English, we often put the preposition at the very end of a question ("Which brush are you cleaning the bowl with?"). In German, you cannot split them up like this. The preposition (mit) and the "which" phrase (welcher Bürste) must stay glued together at the front of the question.
Why is it den Napf and not der Napf?
Napf (bowl/pet dish) is a masculine noun. In this sentence, it is the direct object—the thing receiving the action of being cleaned. Direct objects require the accusative case, which changes the masculine article from der to den.
Is putzen the only word for "to clean" in German?