thought to represent exclusive common innovations in the South Slavic language group. They are prevalently phonological in character, whereas morphological and syntactical isoglosses are much fewer in number. list the following phonological isoglosses: Merger of yers into schwa-like sound, which became in Serbo-Croatian, or split according to the retained hard/soft quality of the preceding consonant into (Macedonian), or (Bulgarian) Proto-Slavic *ę > Proto-Slavic *y > , merging with the reflex of Proto-Slavic *i Proto-Slavic syllabic liquids *r̥ and *l̥ were retained, but *l̥ was subsequently lost in all the daughter languages with different outputs (> in Serbo-Croatian, > vowel+ or +vowel in Slovene, Bulgarian and Macedonian), and *r̥ became in Bulgarian. This development was identical to the loss of yer after a liquid consonant. Hardening of palatals and dental affricates; e.g. š' > š, č' > č, c' > c. South Slavic form of liquid metathesis (CoRC > CRaC, CoLC > CLaC etc.) Most of these are not exclusive in character, however, and are shared with some languages of the Eastern and Western Slavic language groups (in particular, Central Slovakian dialects). On that basis, argues that South Slavic exists strictly as a geographical grouping, not forming a true genetic clade; in other words, there was never a proto-South Slavic language or a period in which all South Slavic dialects exhibited an exclusive set of extensive phonological, morphological or lexical changes (isoglosses) peculiar to them. Furthermore, Matasović argues, there was never a period of cultural or political unity in which Proto-South-Slavic could have existed during which Common South Slavic innovations could have occurred. Several South-Slavic-only lexical and morphological patterns which have been proposed have been postulated to represent common Slavic archaisms, or are shared with some Slovakian or Ukrainian dialects. The South Slavic dialects form a dialectal continuum stretching from today's southern Austria to southeast Bulgaria. On the level of dialectology, they are divided into Western South Slavic (Slovene and Serbo-Croatian dialects) and Eastern South Slavic (Bulgarian and Macedonian dialects); these represent separate migrations into the Balkans and were once separated by intervening Hungarian, Romanian, and Albanian populations; as these populations were assimilated, Eastern and Western South Slavic fused with Torlakian as a transitional dialect. On the other hand, the breakup of the Ottoman and Austro-Hungarian Empires, followed by formation of nation-states in the 19th and 20th centuries, led to the development and codification of standard languages. Standard Slovene, Bulgarian, and