Please help me understand the declensions in this sentence: Vielleicht wirst du eines Tages Tierärztin!"

Question

Vielleicht wirst du eines Tages Tierärztin!

I dont understand the 'es' in "eines Tages" above. Is it possessive? or neutral. Are the declensions based on "du" or "Tierärztin". HELP! lol

Answer 1

It's genitive, yes, but not possessive. While one implies the other in English and many other languages, that is not the case in German. The genitive has much wider applications in German than possessive only.

In particular, this is what is called a genitivus temporis in Latin and is used to describe a rough timeframe ("someday" == "eines Tages"). This form of the genitive is dying out and mostly only present in standing expressions (like the one you found).

Answer 2

The phenomenon is called "Adverbialkasus" (adverbial case), i.e. case for marking an adverbial function, see https://de.wikipedia.org/wiki/Adverbiale_Bestimmung#Substantive

The point is that a time adverbial is not governed by the verb, so it is not the kind of case you get with objects of the verb. But an adverbial often needs some kind of marker in order to indicate what kind of adverbial it is. Often you use prepositions for this purpose, but case is an alternative (in languages like Hungarian, case endings do most of the work of the prepositions in English or German). In German you get genitive case on time adverbials to indicate temporal location (your example) and accusative case to indicate duration ("einen Augenblick zögerte er"). It is true that these items have a tendency to become fixed expressions, as the other contributors have noted.

English allows adverbial noun phrases to go unmarked, like "one day" (see also the wikipedia link above). That's propably what you are used to and what makes you wonder about the genitive in German. But in fact, English is the odd one out in this case.

Answer 3

Tofro's answer is technically right, but incomplete.

The phrase »eines Tages« does not feel like a genitive to German native speakers, although it is. Different than other usages of genitive case, this specific kind of genitive does not depend on anything. Other kinds of genitive always depend on something else, but »eines Tages« does not depend on a verb (»Wir gedenken des Toten«), it does not depend on a preposition (»Wir haben trotz des Umbaus geöffnet.«) and it does not depend on the existence of a noun whose possessive attribute it is (»Das Auto des Lehrers ist blau.«)

The phrase »eines Tages« is a fixed phrase, that can't exist in other cases. You also find it only in its genitive form in dictionaries like leo.dict.org, reverso or cambridge.

someday; some day = eines Tages; irgendwann

Answer 4

It's genitive but not a possessive genitive. The individual cases have multiple functions in German.

Eines Tages is a so called genitivus temporis, meaning some day. Those are in general fixed phrases in German.

You can also say eines Nachts — some night. Another common example is des Nachts, meaning during the night. But des Tages does not exist as a genitivus temporis.

So learn those as fixed phrases.