of Standard Russian and . Another Northern dialectal morphological feature is a post-posed definite article -to, -ta, -te similarly to that existing in Bulgarian and Macedonian. In the Southern Russian dialects, instances of unstressed and following palatalized consonants and preceding a stressed syllable are not reduced to (as occurs in the Moscow dialect), being instead pronounced in such positions (e.g. is pronounced , not ) – this is called yakanye (). Consonants include a fricative , a semivowel and , whereas the Standard and Northern dialects have the consonants , , and final and , respectively. The morphology features a palatalized final in 3rd person forms of verbs (this is unpalatalized in the Standard and Northern dialects). Some of these features such as akanye and yakanye, a debuccalized or lenited , a semivowel and palatalized final in 3rd person forms of verbs are also present in modern Belarusian and some dialects of Ukrainian (Eastern Polesian), indicating a linguistic continuum. The city of Veliky Novgorod has historically displayed a feature called chokanye or tsokanye ( or ), in which and were switched or merged. So, (tsaplya, 'heron') has been recorded as (chaplya). Also, the second palatalization of velars did not occur there, so the so-called ě² (from the Proto-Slavic diphthong *ai) did not cause to shift to ; therefore, where Standard Russian has ('chain'), the form is attested in earlier texts. Among the first to study Russian dialects was Lomonosov in the 18th century. In the 19th, Vladimir Dal compiled the first dictionary that included dialectal vocabulary. Detailed mapping of Russian dialects began at the turn of the 20th century. In modern times, the monumental Dialectological Atlas of the Russian Language ( – Dialektologichesky atlas russkogo yazyka), was published in three folio volumes 1986–1989, after four decades of preparatory work. Comparison with other Slavic languages During the Proto-Slavic (Common Slavic) times all Slavs spoke one mutually intelligible language or group of dialects. There is a high degree of mutual intelligibility between Russian, Belarusian and Ukrainian, and a moderate degree of it in all modern Slavic languages, at least at the conversational level. Derived languages Balachka, a dialect spoken in Krasnodar region, Don, Kuban, and Terek, brought by relocated Cossacks in 1793 and is based on the southwest Ukrainian dialect. During the Russification of the aforementioned regions in the 1920s to 1950s, it was replaced by the Russian language. Esperanto has some