How can I tell the case of *der alten Frau* in this sentence?

Question

I am following the book German for Reading: A Programmed Approach and on page 200 there is a question asking the case of the bold word in the following sentence:

Keiner wird der alten Frau die Wahrheit sagen.

The answer is dative, which translates the sentence into

Nobody will tell the old lady the truth.

However, why can't "der alten Frau" be genitive? It looks satisfying all grammar requirements, and the sentence can be translated into

Nobody will tell the old lady's truth. / Nobody will tell the truth of (about) the old lady.

Answer 1

If you look at the sentence part "der alten Frau" in isolation, it could indeed be either dative or genitive. But you must also consider the context.

Genitive can occur in two functions in German:

• as a possessive, i.e. to indicate ownership ("das Haus der alten Frau") or belongig/relationship ("der Ehemann der alten Frau")
• as genitive objects for verbs that take a genitive object: "Ich gedachte der alten Frau."

The verb "sagen" can't take a genitive object, so we can rule out the second function (genitive object).

For the first function (possessive), it's a bit more subtle, as the word order can be changed to a less usual one:

• "das Haus der alten Frau" ≅ "der alten Frau Haus"
• "der Ehemann der alten Frau" ≅ "der alten Frau Ehemann"

Note though, that in these inverted forms, the definite article of the "possession" has to be dropped. (Which kinda makes sense also semantically: By first naming the "possessor", we already convey a definite meaning. And as Skobo Do pointed out in their answer, it works the same in English, too.)

So, because "die Wahrheit" has its definite article, "der alten Frau" can't be possessive (the old lady's truth) and the only remaining option is that it's the dative object. (Which corresponds to the indirect object in English: To who the truth is being told (or in this case: not told).)

Which verbs accept which object cases and/or prepositions (and for what meanings/roles of the object) is something that has to be learned or looked up verb by verb. While there is some correlation between cases/prepositions and role semantics, there's no hard and fast rule to determine the correct case regime for arbitrary verbs. (That's how it is for English, too, by the way.)

Answer 2

You answered it by yourself.

In English you say

lady's truth

, not

lady's the truth

It is the same in German.

Answer 3

In order that "der alten Frau" can be genetive, the structure of the sentence has to be changed. It would say "Keiner wird die Wahrheit der alten Frau sagen." You have to put the part that concerns the genetiv of the old woman, in front of it. Otherwise there is no direct connection to the old woman and it would stay dative.

Answer 4

My rule of thumb in these situations is to look at word order. With practice you begin to "feel" (or hear) these situations and not have to "figure it out." It's common in German for the indirect object in a sentence to come in the third position after the subject and verb. E.g., Er hat mir das gestern gesagt. or Er sagte mir das gestern. -> "he told me that yesterday." Or, Ich habe der alten Frau das gestern gesagt -> "I told the old woman that yesterday."

In your example you have this word order:

"(1-subject:) Keiner
(2-auxiliary verb:) wird
(3-indirect object:) der alten Frau
(4-direct object:) die Wahrheit
(5-verb infinitive:) sagen."

Unless you are dealing with some literary text or more elevated diction, or dealing with a verb that takes the genitive case, I would go with the default word order described above as your best guide. It will usually lead right to the correct meaning.