Correct usage: "für die Menschen" or "für den Menschen"? Accusative or dative (idiomatic exception)?

Question

When reading Was für eine Krankheit ist Diabetes?, I came across a sentence:

Traubenzucker ist lebenswichtig für den Menschen. [emphasis added]

German grammar tutorials, for example: Prepositions Part 1: The Accusative 7 say that an accusative article or pronoun follows für in a sentence.

Plural die Menschen (nominative/accusative) becomes den Menschen in dative.

Searching on Google (with quotation marks) for hits gave:

• "für die Menschen": 22,800,000 results
• "für den Menschen": 15,600,000 results
• "für die Leute": 17,700,000 results
• "für den Leuten": 55,500,000 results

I am not sure what to make of the search results. Dative following für: is it idiomatic, colloquial, regional or an exception like the wegen den Regen mentioned in The Awful German Language by Mark Twain?

Is there a pattern for such deviations from rules?

Answer 1

The prepositional object [für + noun] does alway require accusative case. And in fact, both of your examples are correct: they are accusatives – they're just not both plural!

für die Menschen — accusative, plural
für den Menschen — accusative, singular

For funsies, here's the complete declination table:

      Singular      Plural
Nom.  der Mensch    die Menschen
Gen.  des Menschen  der Menschen
Dat.  dem Menschen  den Menschen*
Akk.  den Menschen* die Menschen

As you can see, plural dative and singular accusative of Mensch are identical.

That said, I don't know of any dialect that consistently uses the dative case for this preposition. I can only think of the Bavarian fia eam – meaning "for him" – which looks like the standard German für ihm (which would be dative).

Answer 2

You got 55,500,000 results after entering "für den Leuten" into the search bar (I had 147,000,000 five minutes ago), but probably not one single result returning "für den Leuten" itself. Firstly, because "für" and "den" are stop-words which Google doesn't include in the search. Secondly, because it is grammatically wrong and chances are that such obvious mistakes rarely find their way into online resources. The declination of "Leute" goes like this:

• wer? — die Leute
• wessen? — der Leute
• wem? — den Leuten
• wen? — die Leute

But there is another aspect of "für den Menschen" vs. "für die Menschen" which so far hasn't been addressed here.

If you say "Traubenzucker ist wichtig für den Menschen", you mean all humans because that is how we all function biologically. So, this is a finding, a resarch result, and it is true for one human, many humans, and all humans alike.

You wouldn't say "Traubenzucker ist wichtig für die Menschen", because the plural would express that dextrose was important for humans as a group which is not a relevant statement.

For the same reason, you would say "Mobiltelefone sind wichtig für die Menschen" rather than "für den Menschen", because a mobile phone is only relevant for at least two persons. Thus, "für die Menschen" is often used by politicians postulating what they think is important for the community as a whole, like "die Menschen brauchen mehr Grün in den Städten", and so on.

This doesn't go for all imaginable cases, but I think it's a guideline for telling when to use the plural or the singular of "der Mensch".

Answer 3

The für den occurrence is just a search mistake. If you want to refine your search, you might want to use Google Ngram. I support the other answers and show herewith that indeed there doesn't exist the possibility of occurrence for "für den":

Ngrams not found: für den Leute
Ngrams not found: für den Leuten