Meaning and word class of “willen” in “um Gottes willen” and “um Himmels willen”?

Answer 1

Good one...

OK, first the striaght-up answer: This is an adverbial phrase with a prepositional complement using a "fossilized accusative" (erstarrter Akkusativ).

Now the long answer: The prepositional complement is "um den Willen" (around/about the will) wit the genitive object "des Himmels" (of heaven), coming together as "Um den Willen des Himmels" (About the will of heaven ==> for heaven's sake). In a process called "grammaticalization" this morphed into "um Himmels willen", whereby the "um ... willen" forms a circumposition (like "um ... zu"), in which the noun "Wille" turned into it accusative form "Willen" and became the postpositional part of the circumpositon as a "errstarter Akkusative" in the lower case "willen".

Alle Klarheiten restlos beseitigt? (Was all clarity removed without trace?) ... ;)

HTH

Armin

Answer 2

It would translate as "For God's Sake." So, Willen is a noun, as evidenced by the fact that the possessive form of Gott and Himmel is used (Gottes and Himmels). Also, it should be capitalized in the example above, since in German nouns are capitalized. That is often a helpful clue as to the part of speech. One quick note: Willen looks similar to the modal verb wollen (to want), which in the 1st and 3rd person form is will. (z.b. Ich will Eis.)