It is a natural process of development of the language, which is still relatively late in High German.The gradual merging of the dative and the accusative to the so-called accumative or object case is a closely related phenomenon. Let’s start with an inventory.
The languages closest to German are:
- Low German, if you count it as your own language
- Dutch and Afrikaans
- Frisian languages
- English and Scots
In Lower German, instead of dative and accusative, there is already only the uniform accumgenus, and the genitive has practically disappeared completely.
Yiddish still has all four cases, but they differ less than in German.
In Dutch and Afrikaans, the genitive has disappeared completely, except in old phrases.The other three cases have collapsed. Only in the personal pronouns have all four cases familiar to us survived.
Unfortunately, I cannot say anything about the three Frisian languages.
The same applies to English and Scots as to Dutch and Afrikaans, except that the klitikon has developed from the genitive, which no longer behaves like a case at all.It is simply appended to the end of a noun or even a whole phrase: Alexanders des Greatn = Alexander the Great‘s.PS: In addition, the personal pronouns of English and Scots dative and accusative have already merged into an accumative.
As you can see, High German is therefore considerably more conservative in terms of cases than the related languages – with the exception of Yiddish, which is almost as conservative as High German.The standardization of German began in the 17th century with publications by scholars. They consciously took a role model in Latin with its five cases and therefore attached importance to the fact that all four cases, of which traces were still found in dialects, were as clearly distinguished as possible. In other words, they were not based on simplicity, but on the complexity of Latin. (For example, the complicated intermediate position on the way to the accumative was cemented firmly: “In a deep, dark forest”. Depths and dark ones are in the accusative here, although the entire phrase is in the dative.[Other interpretation: For adjectives, there are two different dative forms, which you have to choose between depending on the situation. One of them is identical to the accusative shape. Without standardization, or if the German language standard were as flexible as the English and Dutch, this problem would have been solved long ago.)
Yiddish is very closely related to German.On the one hand, because it originated from the “Jewish German” of the Middle Ages, which was interspersed with Hebrew words and written in Hebrew and spoken by German Jews, and maintained contact with the German dialects over the centuries. On the other hand, however, I have heard that the expansion of Yiddish into a literary language was mainly carried out by Originally Eastern European Jewish intellectuals living in Vienna and was therefore strongly influenced by High German. In addition, East Yiddish is influenced by Slavic languages, which are even more conservative than German in terms of cases.
The case endings of the reconstructed proto-Indo-European “primary language” probably originated from postal positions.Postal positions are like prepositions, but they are based on the word or phrase to which they refer. They are still standard in languages such as Finnish or Hungarian. In modern Indo-European languages, on the other hand, prepositions are the norm, and postal positions arise only occasionally from phrases. Wikipedia lists examples of post positions in German: Postposition.
These post positions gradually grew with the words before them and thus became endings.They are now unstressed appendages to nouns and adjectives. Because they are unstressed and usually not important for understanding, they are gradually being pronounced more and more indistinctly. This leads to combined fall endings such as the accumulating. But the genitive endings are quite important for understanding – at least if the genitive is possessive. This explains why the genitive is so often replaced by longer formulations in other cases (“the wife of my brother”, “my brother his wife” – the latter corresponds exactly to a Latin construction!) or by klitika as it has been replaced, but not completely disappeared.
In English and French, the previous function of the cases has been replaced, where necessary, by prepositions such as the of/de and to/a.In French, de already begins to grow together with the following word, at least when it begins with a vowel.(Then de becomes d’.) It is likely that one day these prepositions will become prefixes that indicate cases.Then the process described above starts again.
PS: You might want to look at other language families.If classical Latin still had 5 cases (the four known from the German plus the ablative; in addition to the vocative), the situation in the modern Romanesque languages resulting from vulgar Latin is the same as in French and English: cases exist there only to a limited extent in personnel pronouns. On the other hand, the Slavic languages usually still have 6 to 8 full cases.