THESE ISOGLOSSES can be established from various points of view.
I. A purely descriptive treatment considers the contemporary state of the Slavic languages without regard to their history. For example, from an articulatory-acoustic standpoint we can draw areal boundaries marking the different pronunciations of the phonemes g (g, y, h) and x (x, h, Ø); separating the different pronunciations of l and ł (ł, l, , w, l); singling out the areas which lack a medio-velar (palatal) r: separating areas that do or do not distinguish voiced and voiceless consonants; areas with three series of prevalar spirants (sic!): s z c Ʒ, š ž č ǯ and ś ź ć ǯ as opposed to areas with two series, i.e., either s z c Ʒ and š ž č ǯ or s z c Ʒ and ś ź ć Ʒ; distinguishing areas with a predominance of vowels over consonants, or vice versa.
II. Isoglosses from the written, visual standpoint; the use of different alphabets.
III. Isoglosses of dialect areas in contradistinction to isoglosses of national or literary languages.
IV. Isoglosses from the standpoint of different changes in originally common, proto-Slavic linguistic material:
Areas with dl, dn, vs. areas with l, n.
Among some Slavs the reflexes of the chronologically first palatalization of the three velars (k, g, x) are distinct from the reflexes of the second palatalization of the three velars, while among other Slavs the reflexes of the palatalizations of k and g differ, hut those of x are identical.
In general the articulatory-acoustic processes connected with the so-called palatalizations and depalatalizations reąuire the establishment of many isoglosses going in various directions.
Among some Slavs the reflexes of nj, Ij, and rj are kept distinct from the reflexes of n, l, r that at one time preceded the palatal (fronted) syllabic vowels i and e etc., while among other Slavs they are not distinguished. The same applies to the combinations of the labial consonants p, b, m, f, v with j and the originally soft (syllabic) sonants. Finally, there is the difference between the reflexes of the consonants: tj, dj, sj, zj and tVi dV, sV\ zV\
The reflexes of pre-Slavic tj and dj, or the proto-Slavic ¿ and d yield the most diverse isoglosses.
Further, there are the various isoglosses marking the distinction or fusion of the proto-Slavic vowels y (Ʒ1) and i (И), ў (Ʒ) and ĭ (ϭ), ĕ () and e (ε).
Special isoglossses mark the different reflexes of the proto-Slavic nasal vowels ę () and o ().
The isoglosses reflecting the diverse reflexes of proto-Slavic ȳ and i, y ( Z ) and 1 ( 5 ) are, in turn, connected with the isoglosses distinguishing the reflexes of the combinations of the velar consonants k g x with the vowels y (Ʒ1) and ў (Ʒ).
Various Slavic linguistic areas can be distinguished by isoglosses which pertain to the influence of consonants on vowels and which concern, in particular, the influence of dental consonants upon the development of depalatalization in vowels and sonants; or the distinction between the features of dentality and that of velarity and labiality.
Isoglosses that represent a boundary between Slavic areas with initial je-, ju- and areas with an initial o-, u-.
We obtain numerous isoglosses if we consider the diverse reflexes of the pre-Slavic and proto-Slavic liąuid sonants ; i, , i and especially the pre- and proto-Slavic or, er, ol, el, occurring both between consonants and in initial position (i.e., the groups called [following Miklosich] tort, tert, tolt, telt, ort, ert, oit, elt).
We may obtain special isoglosses by focusing on the diverse Slavic processes of secondary lengthening of vowels, or of the socalled “compensatory lengthening” (productio suppletoria, Ersatzdehnung), which resulted mainly from the loss of the vowels ў (Ʒ) and ĭ (Ʒ) and on the reflexes of alternation of vowels with “zero.”
By means of isoglosses we can show the boundaries of Slavic areas which do or do not possess the distinction of proto-IndoEuropean and proto-Slavic intonations, the psychological distinction of length (ąuantitas temporalis) of vowels and syllables, distinctions of accent or of stress (ictus) which concern the accentuation of certain morphemes of the word (the morphological use of stress), or of certain syllables of the word (the syntactic use of stress).
V. The Slavic linguistic world also yields a number of distinct areas from a morphological standpoint. Special isoglosses define the borders of areas that have retained the original types of wordstructure, and of their combinations, or which have formed new ones. In some territories suffixes predominate, and in others prefixes and prepositions. Along with a prevailing centralized (“synthetic”) structure, we encounter manifestation of a decentralized (“analytic”) structure; along with syntagms that have coalesced into a single unit, we find special morpheme-syntagms expressing certain formal concepts; there exist both preand postpositional determinants of gender (“articles”); there is the loss of inflectional declension and its replacement by agglutination; diversity of grammatical gender (physiological, biological, and sociological genders); the continuation of one or another morphological type of declension, conjugation, and word formation; the preservation of three numbers (singular, plural, and dual) and the disappearance of the dual; diverse relations of declension types (nominal and pronominal declension, adjectival and numeral declension, etc.). In the system of the verb, a difference in the retention of the verbi finiti not only in the forms of the present tense, but also in the forms of the preterite (aorist, imperfect); formal similarity of the future and the present tenses vs. the formation of the future tense by means of various auxiliary verbs; the retention of a special form of the infinitive or its disappearance and replacement by a substantivum verbale; the differentiation or identification of the supine and the infinitive.
Thus, the map of the Slavic linguistic world presents also from a morphological standpoint a network of various isoglosses.
VI. Finally, it is desirable to draw isoglosses distinguishing Slavic areas that have been subject to various foreign influences (tribal, religious, or national) and those which have been formed either through oral-aural contact or through graphic-visual impressions. We can distinguish the Slavic East, which has been subject primarily to Graeco-Byzantine influence, and the Slavic West, which fell under the power of Rome and its Romano-Germanic successors. In addition, one must take into account the influence of some Slavs upon others (the role of Church Slavic, Czech, Polish, etc.), as well as the influence of Germanic (German, English, Scandinavian), Romance (French, Italian, Roumanian), of Finno-Ugric (Hungarian, Finnic), Turko-Tartar and others.