Slavic languages. A group of languages within the Indo-European language family. They developed out of the dialects of Proto-Slavic, an ancestral language that arose between the Oder River and the Dnipro River. Today there are 12 Slavic languages: Belarusian, Russian, Ukrainian (see Ukrainian language), Czech, Lower Sorbian, Polish, Slovak, Slovenian, Upper Sorbian, Bulgarian, Macedonian, and Serbo-Croatian. Of the historically recorded languages Polabian is extinct. In the period of its disintegration, Proto-Slavic consisted of a continuum of dialects. The contemporary Slavic languages were formed as a result of the unification of particular dialects around political and cultural centers.

The traditional conception of the history of language as constant disintegration is false: the theory that Proto-Slavic split first into Proto–East Slavic, Proto–West Slavic, and Proto–South Slavic are not supported by historical or linguistic facts. The widely accepted division of the Slavic languages into three groups—East, West, and South (or, less accepted, North, Central, and South)—is merely conventional and can be justified only from a geographic perspective. In reality, with the exception of regions of later colonization, the boundaries between the Slavic languages have been fluid. There are transitional dialects between them, and even between the literary languages the transitions are gradual.

The principle according to which the Slavic languages have been grouped is primarily a genetic one. Structurally they have much in common if one compares them in geographically contiguous pairs. There are, however, few traits common to all of them. For example, in prosody, phonemically relevant intonation in stressed vowels exists only in Slovene and Serbo-Croatian; lengthened vowels exist in Slovak and Czech; and stress is fixed in Polish, Slovak, Upper and Lower Sorbian, Czech, and Macedonian. In phonetics, Polish has nasal vowels, Czech and Slovak have diphthongs, and Slovenian and Macedonian have no opposition in the palatalization of consonants. In morphology, nouns are indeclinable only in Bulgarian and Macedonian, and conjugation is split only in Serbo-Croatian, Bulgarian, and Macedonian.

Traits common to all the Slavic languages are synchronically evident partly in the principles of their construction and partly in their material elements. Traits of the first type are, for example, the alternation of particular vowels with a zero morpheme (although which vowel alternates varies by language; cf Ukrainian son : snu, Polish sen : snu, Serbo-Croatian san : sna ‘dream’ nom : gen), similarities in the root structure, the existence of two stems in the verb versus one usually in the noun, and agreement of the adjective with the noun. The most obvious material similarities are in vocabulary and, even more, in the repertoire of word roots (often, however, with a semantic shift; eg, Ukrainian hora ‘mountain’ vs Bulgarian gora ‘forest’, Ukrainian šum ‘din’ vs Serbo-Croatian šuma ‘forest’), particularly in the set of prepositions and prefixes (with partial differences) and, less often, of suffixes.

[This article originally appeared in the Encyclopedia of Ukraine, vol. 4 (1993).]