Breakdown of Sie will häkeln, aber ich weiß nicht, wie groß der Vorrat an Perlen ist.
ich
I
sein
to be
sie
she
groß
big / tall
Questions & Answers about Sie will häkeln, aber ich weiß nicht, wie groß der Vorrat an Perlen ist.
Why do we use the preposition an here instead of von for 'supply of'?
The noun der Vorrat (the supply or stock) strongly pairs with the preposition an plus the dative case to specify what the supply consists of. While you might occasionally hear von in casual speech, Vorrat an is the standard, natural-sounding combination.
Since this lesson is about the indefinite pronoun welche, could I use it here to mean 'a supply of some'?
No, you cannot use welche right after the preposition an just to mean the English word 'some'. The pronoun welche completely replaces a noun rather than describing an unspecific amount next to a preposition. You would use it in a follow-up sentence like Braucht sie welche? (Does she need some?).
Why is the verb ist at the very end of the sentence?
The phrase starting with wie groß is an indirect question. Indirect questions act as subordinate clauses in German, which means the conjugated verb (ist) must be pushed to the very end of the clause.
What is the case of Perlen in this sentence?
It is in the dative case. The preposition an requires the dative here because it describes a static state or concept (a supply of beads), not a physical movement or direction toward a goal. Since Perlen is plural, it already ends in an -n, which perfectly fits the dative plural rules.