Some types of assimilation at morphemic seams in Siberian Turkic languages

Rules of consonant compatibility define languages in very particular ways. They characterize a language just as strongly as its phonemic structure. Specific traits of sound combination formations depend on several parameters, primarily on the fact whether these processes occur within the root, the word stem, or during the addition of affixes. We primarily observe the latter (addition of derivational and inflectional affixes). In Turkic languages, affixes starting with consonants may be combined with word stems ending with consonants by various means: the number of affix variants largely depends on this. The number of allomorphs formed by variants of initial consonant shows the ease of sound combination in each language. Affixes starting with consonants may be attached with the help of copulative vowels. Ex.: бар-ы-ма! ‘don't come!', бар-ы-ман! ‘don't come (Plur..)!' (Yakut). Affixes attached with the help of a copulative vowel (not changing the initial consonant) were common in Old Turkic and remain common in Yakut: =мсый/=ымсый, =ргаа/=ыргаа, =талаа/=ыталаа. In other Turkic languages, it is possible to view as single-variant the affixes where the choice between consonants and vowels in the beginning depends on the end of the word stem: Acc. таба=ны ‘reindeer', but ат=ы ‘horse', эт=и ‘meat'. Second way: the word stem ending with a consonant is directly combined with an affix starting with a consonant, and various types of assimilations occur at the morphemic seam: progressive, regressive, progressive-regressive, full, and partial. In Turkic languages, the most common type is progressive assimilation where the initial consonant of an affix changes depending on the final consonant of the word stem. The change of patterns in sound compatibility directly influences the phoneme paradigms, broadening or narrowing down the possibilities of their opposition, as well as allomorph variations and structures of morphological paradigms. Consonants are combined according to specific patterns which characterize specific languages and types of languages alike. In the language of runic Turkic literary monuments, only sonorant + obstruent consonant combinations were possible in single-syllable root morphemes. This pattern is also preserved in modern Turkic languages. However, the following combinations occurred at morphemic seams in runic literary monuments: voiceless obstruent + voiced obstruent, voiced obstruent + voiceless obstruent, obstruent + sonorant, sonorant + voiceless obstruent, sonorant + voiced obstruent. Combinations based on the principle of dissimilation (contrastive compatibility) existed in runic text, which possibly served as border markers at morphemic seams and supported the transparence of the morphemic structure. High frequency of sonorants in affix anlaut (combined with their relatively low frequency in word anlauts) also served as a marker of affixes. In Siberian Turkic languages (as well as several Kipchak languages: Kyrgyz, Kazakh, etc.) we may observe a process that can be characterized as a transfer of phonotactic patterns typical from single-syllable root morphemes to intra-morpheme consonant combinations. This prompted the process of change of basic affix variant in Siberian Turkic languages: affixes that used to contain sonorants in anlaut (in Old Turkic) now contain voiced consonants: -ма > -ба. This process is still developing and is steadily absorbing affixes with anlaut -м, and less frequently with -н; examples with -л (after vowels) have not been observed. Special research is required due to the fact that some combinations are only found within word stems, or only at morphemic seams, or both. These differences may be caused by preservation of more ancient forms in word stems that are currently indivisible. Processes of assimilation at morphemic seams lead to obscuration of morphemic structures and complication of grammatical paradigms. Distinctive patterns of attachment of affixes starting with vowels also o