Common Slavic. Language that developed from Common Indo-European and that, in its disintegration, gave rise to the historically attested Slavic languages. Common Slavic has not been preserved in notation; its structure and history have been reconstructed by means of the comparative method. The differentiation of Common Slavic from Indo-European began about 2000 BC with the following changes: (1) the loss of aspiration in voiced consonants; (2) the loss of labialization in velar consonants; (3) the loss of syllabicity in resonants (, became ir ~ ur, il ~ ul); (4) the appearance of x from s after i, u, r, k; (5) the loss of palato-velars (k', g' became s, z); (6) the coalescence of o and a; (7) the development of phonemic pitch in long vowels. The Baltic and Indo-Iranian languages shared some of these changes with Common Slavic. During the early Christian era Common Slavic, which had a highly developed system of phonemic oppositions in vowels, underwent a number of simplifications of its consonant clusters, lost word-final consonants, and developed prothetic consonants before word-initial vowels. As a result of these changes as well as the monophthongization of diphthongs, by about the 6th century AD Common Slavic was a language characterized by a predominance of open syllables. With the further process of reciprocal assimilation of vowels and consonants within the syllable, there took place (1) three palatalizations of velar consonants before (and, partly, after) front vowels (5th–9th century), which caused the inventory of Common Slavic consonants to increase, and (2) two delabializations of labialized vowels (7th–9th century).

Nothing is known of the dialectal differentiations of Common Slavic prior to the 6th century AD. If such dialectal peculiarities did exist, they were probably lost during the great migrations of the Slavs, who, starting in the 5th and 6th century, gradually came to occupy the expanses of the Balkan peninsula, central Europe, and central and northern Russia. Many linguistic changes, which did not affect the Common Slavic language as a whole and were therefore of a dialectal nature, can be reconstructed for the period beginning in the 6th or 7th century. The isoglosses of this period run in various directions, sometimes crossing each other, and coincide neither with the boundaries of the three traditionally accepted groups of the Slavic languages (West, East, South), nor even with the boundaries of later Slavic languages. This is the period of the disintegration of Common Slavic, but prior to the formation of the historically attested individual Slavic languages. Certain parallelisms exist among the linguistic changes of this period and those of later periods in various parts of the territory of the Slavic peoples (eg, jers were lost in all parts, although that loss took place in various areas at different times during the 9th–13th century and had more or less divergent consequences). But the general trend in the 8th–12th century led rather to the accumulation of linguistic differences and thus to the gradual formation, in the long run, of structurally highly differentiated languages. Several of these languages reinstated, on a new foundation, the system of pitch oppositions in vowels and the predominance of open syllables that characterized Common Slavic (eg Serbo-Croatian); others lost the pitch oppositions in vowels, limited the role of open syllables, and developed the opposition in the palatalization of consonants (eg Russian, Polish). (See Common Russian for more on the differentiation and, specifically, on the formation of the Ukrainian language.)

In morphology, Common Slavic inherited from Common Indo-European a rich and diversified inflection of nouns and verbs. The Common Slavic nominal and pronominal declensions yielded to many partial changes (stemming primarily from phonetic changes of the late period of Common Slavic) but survived as a system up to the historic period and into our time in all of the Slavic languages except Macedonian and Bulgarian. Yet even in late Common Slavic the transition had progressed from a nominal declension based on stems to one based on gender and on nominative case endings. The compound declension (which combined nominal and pronominal endings) became characteristic of adjectives; it was also formed in the late period of Common Slavic. However, verb conjugation underwent a fundamental restructuring, possibly still in the early period of Common Slavic. The Indo-European imperfect, perfect, and future were lost, as were the imperative and the optative (which was transformed into the new imperative), and forms of the middle voice. A new infinitive was developed. During the late Common Slavic period, the new imperfect and perfect arose, the formation of a new future tense had begun, and verbal aspects were developing rapidly.

BIBLIOGRAPHY
Shevelov, G. A Prehistory of Slavic (Heidelberg 1964, New York 1965)
Sławski, F. (ed). Słownik prasłowiański, 4 vols (Wrocław 1974, 1976, 1979, 1981)
Trubachev, O. (ed). Etimologicheskii slovar' slavianskikh iazykov. Praslavianskii leksicheskii fond (Moscow, in fascicles since 1974)
Birnbaum, H. Common Slavic: Progress and Problems in Its Reconstruction (Ann Arbor 1975)

George Yurii Shevelov

[This article originally appeared in the Encyclopedia of Ukraine, vol. 1 (1984).]