THE PLACE OF THE CASE CATEGORY İN THE LANGUAGE SYSTEM

The case category is a grammatical category that exists in most of the world’s languages, but it is not a single system for all languages, it is a grammatical category that appears with its own characteristics due to the laws of development of each language. Although there are several types of case in world languages, for Turkish languages there is one type is characteristic. In the Orkhon-Yenisei monuments, there were nine cases of the noun, the ninth case was called the instrumental-joint case. The same situation can also be found in Uighur written monuments. In modern times, the joint case in the Kazakh, Karachay-Balkar, Karaim, Kha-kas, Shor, Chuvash, and Yakut languages existed as the seventh case in the grammar books of the Azerbaijani language until 1939, but later it was removed from the textbooks and only six cases were preserved. Methods: Since the case category exists historically in world languages, including Turkish and Azerbaijani languages, diachronic, synchronic, as well as comparative-historical and comparative-typological methods were used in the article.


Introduction
In Turkology, as well as in Azerbaijani linguistics, the case category and the study of morphological features belonging to this category have always been in the center of attention, although a lot of research and studies have been carried out in this field until now, the functional-semantic features of individual cases, morphological features reflecting different cases and their origin, there are still many unsolved problems related to issues such as historical case substitutions.This feature was also manifested in the case category, "although some slight differences appeared in the formal signs of this category, they were mostly preserved in all periods" (Mirzazade H.,1990). Researches show that "Case suffixes, which create a connection between word combinations and words within a sentence, and connect them grammatically, performed the same function in ancient Turkish written monuments.However, the cases of the noun are different from the modern case suffixes according to the number, and the case suffixes differ from the phonetic composition" (Khudiyev N., 2015).

Declension possibilities of nouns in world languages
"The case of nouns is not a uniform system for all languages of the world, but due to the laws of development of each language, it appears with its own characteristics.For example, while Russian has three types of declension of nouns, Turkish has one declension system.(Mammadov N., 1971) N. Dmitriyev also pointed out this fact and shows that "unlike other group of languages, Turkish languages have a certain state.In other words, Turkish languages do not have the first, second, and third cases in Russian, or the strong, weak, and mixed cases in German" (Dmitriev N., 1962).
А. Shukurlu shows that it is possible to find the traces and remains of the case suffix "-in the content of some words that have been stabilized as an isolated lexical unit in the current Turkish languages.The instrumental-combination case suffix expressed by the suffix variants of -ın, -in, -un is also found in Uyghur written monuments" (Shukurlu A., 1993).
It should be noted that in the modern Karachay-Balkar language, the joint case -tın, -ın, -nı (djoltun keledi -comes with way), and in the Karaim language, it is formed through the suffixes -ba, -bye, be (atimba, kezibe).In the Shor language, the conjunction is formed by the case element -ba, -be, which can be considered as a remnant of the ancient conjugation.
Therefore, the case category is structurally fully formed in Turkic languages, as well as in Azerbaijani, as a category that is realized according to its morphological features and finds its true confirmation.
It is also clear from what has been said that the case category has a special place and role in the grammatical system of our language, and has not undergone significant changes historically in most Turkish languages.In the literature of linguistics, it is rightly called "a category arising from morphological requirements in form and syntactic requirements in function" (Huseynzade M.,1973) is considered.

Case category in Azerbaijani and other Turkic languages
In the Azerbaijani language, as well as in all other Turkic languages, the case cat-egory has a stable and formed system, and although it is mostly common, it differs to a certain extent in terms of the multivariation of its morphological features and the number of cases.Therefore, "it is impossible to think about when this category was created in Turkic languages.However, the existence of the perfect case system of nouns in the Goyturk (Orkhon-Yenisei) inscriptions, which are the oldest written monuments of Turkic languages, allows us to say that the category of case in Turkic languages was formed in the inaccessible depths of history".(Asadova A., 2009) Türk the stability of the case system in itself is a fact that shows the stability of its grammatical structure, but it is also an indicator of the antiquity of these languages.About 1.500 years have passed since the establishment of the Turkish state by Il Khagan and the emergence of the Turkish script.
So far, the case category has been given different definitions in the linguistics literature.Although all these definitions are aimed at explaining the basic nature of the phenomenon, there is still no complete and precise definition in this direction.As early as "in 1934, in the textbook "Grammar" written by associate professors I. Hasanov and A. Sharifov, "Cases of Nouns" was given as a special topic and it was noted that "Nouns are used without a suffix when they are in a sentence, but when they are complete, they take a suffix.This called noun declension.(Zeynal S., 2017).In the "Grammar" textbook written by A. Demirchizade and D. Guliyev in 1938, case suffixes and cases are defined as follows: "Nouns change in meaning and form.This change is called noun declension.The suffixes that nouns take to perform certain functions in the sentence and change their meaning are called case suffixes.(Demirchizade A.,1938) In the book "Grammar of the Azerbaijani Language" (Part I) published by the Azerbaijan Academy of Sciences in 1951, the case is considered the main tool for distinguishing the noun from the verb, the concepts of case and case are defined separately: "The formation of a noun in a syntactic relationship with different words is called a case.The case of the noun by means of modifying suffixes is called the case of the noun (Grammar, 1951).In the book "Modern Azerbaijani language" of the Institute of Linguistics named after Section 3. Philology ANAS Nasimi, the concepts of case and declension are not separated, the definition of declension is shown as follows: "The declination of nouns is called the declination of nouns according to the requirements of verbs, conjunctions and a number of nouns within a word combination and sentence" (Modern, 1980).
In the dictionary "Explanatory Linguistic Terms" compiled by M. Adilov, Z. Verdiyeva, F. Magayeva, the concepts of case and case are explained as follows: "Case -1.It is one of the grammatical categories belonging to the noun, and indicates the relationship of the object it reflects with other objects, actions, signs.2. It is one of the forms of the noun and reflects the relation of that noun with other words in the word combination and sentence.
Declension -The subordinate word takes different case suffixes according to the requirement of the governing word" (Adilov M.,1989).
As it can be seen, the morphological and syntactic nature of the case category is shown in the dictionary in the form of separate clauses, and the case is explained as the change of the case suffixes of the controlled party.In B. Khalilov›s textbook "Morphology of the Modern Azerbaijani Language" (Part I), the case category is presented as a morphological-syntactic category, and this category is referred to as a general grammatical category and given the following definition: "A combination of words that can be resolved and verbs and conjunctions within a sentence, when names change from one form to another according to the demand, it is called transformation" (Khalilov B., 2000).In the textbook "Morphology of the Modern Azerbaijani language" published by J. Jafarov and N. Abdullayev in 2004, declension was presented as one of the main morphological signs of nouns and it was shown that "Changing nouns according to the requirements of noun, adjective, number, pronoun, verb and adverb is called declension" (Jafarov C., 2004).G. Kazimov shows that case changes play a special role in the creation of relationships between the thing that is the basis of material existence and its movement, and writes that "Nouns change by accepting different case suffixes.The total number of case changes of a noun is called case (Kazimov K., 2010).
Here, it is appropriate to remind S. Rustamova opinion that "There is no universally accepted idea about the exact definition and boundaries of grammatical categories, not only in Azerbaijani linguistics, but also in general and Russian linguistics" (Rustamova R., 2004), but we think that researchers› research in this direction and separate it is necessary to consider his efforts to give more complete definitions to separate grammatical concepts and categories, to define the boundaries of grammatical categories more correctly.From this point of view, although the definition presented by B. Khalilov is more acceptable among the definitions mentioned above, since the expression "words that can be used" is not as clear as the linguistic term, we consider it appropriate to give such a definition to use: The case category has historically undergone an interesting development path in our language, while retaining its ancient characteristics, it has become even richer.Researches show that "case suffixes, which at first glance are clearly distinguished by common Turkish formats, actually have very complex morphological features.The emergence of such a complex situation is related to the grammatical semantics of case suffixes and the different functions of the same morpheme" (Jalilov F., 1988).
As a result of his research on the language of the Orkhon-Yenisei monuments, Y. Mammadov, who considers the substitution of noun cases by function as a legitimate feature of ancient Turkish written monuments, draws attention to the fact that these facts are widespread and shows numerous examples (Mammadov Y., 1979).
When we examine the ancient written sources of the Azerbaijani language and the creativity of our classics, it is clear that the historically stable forms of our language are mostly consistent with the Orkhon-Yenisei monuments."The case suffixes of the noun, which have a poetic characteristic in the poetry branch of the classical style with a number of morphological features, have led to the liberation of our literary language from the series of adverbial compositions" (History, 2007).

Conclusion
The case category has an important role in the language system as a category that has a strict system in the grammatical structure of different world languages, manifests itself according to the internal capabilities of each language and serves the correct connection of words and word combinations in the speech process.
In the Azerbaijani language, as well as in all other Turkic languages, the case category has a stable and formed system, and although it is mostly common, it differs to a certain extent in terms of the multivariation of its morphological features and the number of cases.The emergence of such a complex situation is related to the grammatical semantics of case suffixes and the different functions of the same morpheme.