Distributive patterns of Circassian vowels and reconstruction of the Common Circassian vowel system

Modern Circassian languages (Adyghe and Kabardian) have a threefold vocalic system based on the degree of openness: open /а/, close /e/, and mid /ə/. The article analyzes the distribution and phonotactics of Circassian vowels in CVCV syllabic chains. The disyllabic words of structure #CVCV# have the following options of vowel distribution: СaСa, СaСe, СeCa, СaСə, СеСе, СеСə, СəСа, СəСе, СəСə. In the sequence /V+V/, the vowel /e/ is always assimilated to /a/, and /ə/ is always assimilated to /a/ or /e/. As in Abkhaz, but unlike in Ubykh, in Circassian languages combinations of vowels are always realized as one vocalic sound (/V+V/ = [V]). Most authors do not question the existence of at least two phonemic vowels in Proto-Circassian. As for the late stage of Proto-Circassian, which can be called Common Circassian, in contrast to the two-term vocalism of the early language, a threefold system *a ~ *e ~ *ə appears to have developed at that point. The contrast *a ~ *e, thus, does not go deeper than the late Proto-Circassian (i.e., Common Circassian) period and is the result of phonologization of the positional allophonic contrast *[a] ~ *[e]. The so-called “rule of two open syllables” is discussed. On the basis of vocalic correspondences between Circassian languages, a three-term vocalic system of Common Circassian is reconstructed. The author also discusses exceptions and irregular vocalic correspondences.