Confused by "lange" as adverb

Question

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.

Answer 1

Lang is an adjective. It is used for both, time and distance. As usual, its corresponding adverb is lang, but there is also the related adverb lange.

The adverb lange is used only temporal: “Das dauert lange”, “Ich habe lange geübt”.

The adverb lang is used mainly spatial: “Ich zieh’ dir die Ohren lang”, “Das Kleid sieht lang aus”, “Hier geht’s lang!”. lange would be wrong here — though I admit, that verbs for spatial adverbs are rare (ziehen, strecken, machen, wirken, erscheinen, aussehen).

But the temporal use of lang is possible as well. It is found often in speech, particularly when it is strongly emphasized: “Er hat laaaang geredet”. An -e behind would spoil the echoism.

Some people consider the temporal use of the adverb lang as slang, sloppy, or even wrong. I cannot second that, as I’m not aware of a rule forbidding it, and I can hear and read it every day.

But of course I’d say “Die Spaghetti müssen lange kochen” — just to make sure, that I don’t expect them to grow ;-)

Answer 2

The problem you have is the difference between Wortart (word class) and Funktion (function).

Adjectives and adverbs are different word classes. Lang is an adjective, lange is an adverb. In general, adverbs can not be derived generically from adjectives in German (in contrast to the english -ly derivative). This is not necessary in German because of the following.

The function in your sentence is that of an adverbial (regard the difference to adverb), which means, that it describes the verb/predicate. Adverbials can be formed by adverbs and adjectives. Consequently, you can use the adverbial lange as well as the adjective lang for your sentence.

Ich muss lange beim Orthopäden warten.
Ich muss lang beim Orthopäden warten.

PS: Normally, you can differentiate adverbs and adjectives by the ability to be declinated. Adjectives can be declinated, adverbs not. Unfortunately, lange looks exactly like a declinated form of lang, so that doesn’t work here and helps your confusion.

Answer 3

So, basically you are right, lange is an adverb. An adverb describes the verb, for example:

He quickly runs.

There is no difference to it in German. If you have to/want to describe the process of a verb, in your example the waiting (warten) process, we need for some specific verbs the -e.

As you said, lang is the adjective, but can’t be the adverb.

(Example: Das ist ein langes Kabel — Note, that the -es comes from Das Kabel)

For that reason we need the -e (like you wrote it in your example)