Query concerning relative pronouns: Is this nominative or accusative?

Question

We’re doing relative pronouns at the moment, and my teacher and I disagree as to how these sentences should be resolved.

Frederika sah einen Beutel. Der Beutel war aus schwarzem Leder.

I propose:

Frederika sah einen Beutel, der aus schwarzem Leder war.

I.e. the relative pronoun is in the nominative, as the second clause means that was made from leather. However she insists that that is in the accusative, as Beutel is in the accusative in the first clause.

Frederika sah einen Beutel, den aus schwarzem Leder war.

Who is right?

Answer 1

You are correct. Reasons:

• If the relative clause started with den, it would not have a subject.

  *den{acc-object} aus schwarzem Leder{description} war{verb — conjugated to what?}

  Technically, sentences without subject are no problem in German, but not with the copula sein.

• The case of the word in the main clause is irrelevant for the case of the relative pronoun: All 16 theoretical combinations are possible.

• Assume the main clause be not there and that the relative pronoun is turned into a demonstrative pronoun. The sentence would become:

  Der war aus schwarzem Leder.

  No questions there, I hope.

Answer 2

Akkusativ ist falsch. Zugrunde liegt:

Frederika sah einen Beutel. Der Beutel war aus schwarzem Leder. (nicht: Den Beutel war aus schwarzem Leder.)

Er war aus schwarzem Leder. / … einen Beutel, der aus schwarzem Leder war.

Answer 3

Jan's excellent answer covers many important points in just a few words. I'll just add the likely explanation of your teacher's confusion.

Your teacher is probably aware that German relative clauses work exactly like English relative clauses in this respect. The problem, however, is that the situation surrounding the one English relative pronoun (who vs. whom) that still distinguishes nominative = subject case vs. accusative/dative = object case has become extremely chaotic in recent decades. See my answer to Is “whom” correct in “I speak of him, whom is…” over at English Language Stack Exchange. I'll quote the four major modern styles of dealing with who/whom from that post:

1. Who is the subject case, whom is the object case. The case of a relative pronoun is determined by its function in the relative clause.
2. The word whom is obsolete. It has been replaced by who in all contexts.
3. The word whom is nothing more than a substitute for who that can be used wherever who can be used, to indicate formality.
4. Who is the subject case, whom is the object case. The case of a relative pronoun is determined by the function of the referent in the main clause.

1 is the original rule that is part of the common heritage of German and English as (West) Germanic languages, and indeed of all Indo-European languages. 4 is a temporary aberration peculiar to English that arose in a situation where many native speakers want to make the prestigious who/whom distinction but get too much 'wrong' (styles 2 and 3) input to infer rule 1 from it. Rule 1 is traditionally taught in the short form consisting only of the first sentence. Combined with so many people using styles 2 or 3, it is a matter of pure accident whether someone interprets this as 1 or 4. Meanwhile the people using style 4 have reached critical mass and some have even started teaching their method under the misconception that it is the traditional, prestigious one. At this point you can't really blame anyone for using style 4.