Breakdown of Geh nicht entlang der morschen Wand dieser Ruine!
nicht
not
dieser
this / that (fem.: diese, neut.: dieses)
gehen
to go
die Wand
the wall
Questions & Answers about Geh nicht entlang der morschen Wand dieser Ruine!
I previously learned that entlang comes after the noun. Why is it placed before the noun here?
You likely first learned entlang as a word that follows the noun and takes the accusative case, as in die Wand entlang (along the wall). However, it can also be placed before the noun. When used this way, it acts as a standard preposition and usually takes the genitive case, or sometimes the dative case.
Is der morschen Wand in the genitive or the dative case in this sentence?
It is technically ambiguous. Because Wand is a feminine noun, its definite article is der in both the dative and the genitive cases, and the adjective ending is -en for both as well. However, because entlang before a noun traditionally demands the genitive case, grammarians would classify this as the genitive.
Why does the adjective morsch get an -en ending to become morschen?
Because it follows the definite article der, which already clearly signals the case and gender, the adjective takes a weak ending. For all nouns in the genitive or dative case, this weak adjective ending is always -en.
Does dieser Ruine also belong to the preposition entlang?
No, dieser Ruine is a separate genitive phrase that modifies Wand. It acts as a possessive meaning "of this ruin". Stacking a genitive phrase directly after another noun to show possession (the wall of the ruin) is a very common structure in German, especially at the B2 level.