On typologically relevant properties of Andic verbal grammatical systems

Despite the fact that Andic languages (< East Caucasian) are widely recognised as agglutinating, their verbal systems barely demonstrate any agglutinating properties. The most important characteristics of these systems are the incomplete orthogonality of grammatical categories and the related properties of semantic non-additivity or morphological idiomaticity. In terms of morphotactic structure, different Andic systems can be either morphotactically complex or simplex. The difference is related to the intensity of fusional processes in the system. The relationship between the structures of semantic and formal oppositions in such systems is opaque. Many formatives in formally additive systems exhibit morphomic properties, and their decreased combinatorial potential is manifested in the hierarchical structure of the paradigm. From a typological perspective, such peculiarities are not unexpected for systems expressing predominantly TAM meanings. The paper proposes a number of diachronic considerations to explain the observed characteristics of the systems. Non-orthogonality and semantic non-additivity can be explained by asynchronous grammaticalization, which prevents the formation of orthogonal categories with additive means of expression and is related to different stability of meanings in the system and different rates of their diachronic renovation. Morphomic and hierarchical structures in the paradigm arise due to layering and grammatical drift leading to polysemic and heterosemic meaning structures of markers.