Complexity of case systems of historical Turkic languages (old Turkic pre-Mongolic period)

The article deals with paradigmatic, syntagmatic and surface complexity of case systems of historical Turkic languages of the Old Turkic period. The paradigmatic (systemic) complexity of the case systems is assessed according to the following criteria: quantity of elements, quantity of their paradigmatic variants (allomorphs), especially if the paradigmatic variation leads to changes in Old Turkic case systems. The surface complexity is the length of elements belonging to the described case systems. The syntagmatic complexity has proved to be the most important criterion in our research. We especially take into consideration the following syntagmatic features of Old Turkic case forms: correlation of case forms with overt markers with the nominative case forms that do not have any overt marker; they coincide with nominal stems; percentage of usage of each case; semantic and syntactic functions of each case form. The Old Turkic period is represented by written documents in various writing systems and on various materials (rocks, everyday objects, paper, pergament, etc.). It embraces the time period of almost six hundred years and covers the huge area in the center of Eurasia. There are three corpora of Old Turkic texts arranged more or less diachronically. The first corpus is represented by runiform Old Turkic texts. These are the oldest Turkic texts, the most ancient ones date back to the 7th century. The second corpus is represented by the so-called Old Yughur texts. It contains texts dating back appr. to the 9th-11th centuries. It is the most rich corpus containing numerous texts belonging to different genres. Inside this period we distinguish three subperiods: the Manichaean one, the classical Old Uyghur one and the late Old Uyghur one. The third corpus is represented by texts in the Arabic writing strongly influenced by the Islam religious tradition and belonging to the 12th-13th centuries. We deal with the early Old Turkic time and describe case systems of the following texts: 1) an extract from the inscription devoted to Tonyukuk, ca. 2500 sounds, representing the first corpus; 2) an extract from the text Huastvanift, ca. 2500 sounds, belonging to the pre-classical period of the Old Uyghur time; 3) an extract from the text Maitrisimit, also ca. 2500 sounds, representing the classical period of the second corpus. Our analysis showed that the inventory of case forms of Old Turkic languages of the earliest period was considerably bigger than that of modern Turkic languages. In the course of this period, many ancient case forms were abandoned, thus the system of case forms became better organized, with fewer forms that are more semantically clear and specific. All this is an indication of less complex language systems. Along with the loss of ancient case forms, some combinations of case forms with postpositions were beginning to get synthesized at that time. The existence of a fusion morpheme denoting both the possessive of the third person and the accusative case and coinciding (in some allomorphs) in form with the ancient instrumental case has probably led to the disappearance of the latter and emergence of the new instrumental marker from the postposition ‘together with, with' in later periods. According to their semantics, case forms of later periods, especially in the classic Old Uyghur time, developed more specific functions as compared with the earliest Old Turkic historical documents.