While learning German on Babbel, I came across this sentence:
Ich muss lange beim Orthopäden warten.
This confused me, because I thought that it should be lang instead of lange. My theory is: We are trying to describe the verb warten, so we need an adverb, and I understand that you can use an adjective without any case endings as an adverb, and since there is an adjective lang, we should be able to use it as the adverb here without adding any e.
Could someone please explain exactly what part(s) of the above reasoning are wrong?
What I’ve tried so far
My question is essentially this question, I think — but I’m struggling to understand the answer (both the reasoning and the language, which is still a bit above my level). At first it seems to agree with my hypothesis that lang is the adverb — it says
Lange ist das Adjektiv zum Adverb lang
but later appears to contradict this with
Etwas dauert / scheint / währt lange
Are lang and lange both adverbs? Or is lange somehow not considered to be an adverb in etwas dauert lange?
Finally, dict.cc reports that lang is both an adjective and an adverb, as I would expect/hope … But also, to my surprise, that lange is an adverb.