accent, including the complex systems of alternating stress in nouns, verbs and short adjectives. Russian consistently preserves between vowels, unlike all other modern Slavic languages. Russian preserves palatalized consonants better than all other East and West Slavic languages, making it important for the reconstruction of yers. The Russian development of CerC, CorC, CĭrC, CŭrC and similar sequences is straightforward and in most cases easily reversible to yield the Proto-Slavic equivalent. Similarly the development of the strong yers is straightforward and preserves the front-back distinction. (But note that Russian shows early development of *CelC > *ColC and *CĭlC > *CŭlC, obscuring the front-back differences in these sequences.) Vowels Loss of yers As with all other Slavic languages, the ultra-short vowels termed yers were lost or transformed. From the documentary evidence of Old East Slavic, this appears to have happened in the 12th century, about 200 years after its occurrence in Old Church Slavonic. The result was straightforward, with reflexes that preserve the front-back distinction between the yers in nearly all circumstances: Strong > , with palatalization of the preceding consonant Strong > , without palatalization of the preceding consonant Weak is lost, with palatalization of the preceding consonant Weak is lost, without palatalization of the preceding consonant See the article on yers for the hypothesized pronunciation of these sounds and the meaning of the strong vs. weak distinction. Examples: Old East Slavic > Russian "about me" Old East Slavic > Russian "sleep (nom. sg.)", cognate with Lat. somnus Old East Slavic > Russian "of sleep (gen. sg.)" The loss of the yers caused the phonemicization of palatalized consonants and led to geminated consonants and a much greater variety of consonant clusters, with attendant voicing and/or devoicing in the assimilation: Old East Slavic > Russian ('where'). Unlike most other Slavic languages, so-called yer tensing (the special development of > and > for some yers preceding ) did not happen in Russian, nor was later lost. Yers preceding developed as elsewhere; when dropped, a sequence Cʲj developed, which is preserved as such only in Russian. (*Cʲj > CʲCʲ in Ukrainian and Belarusian; elsewhere, it generally merged with *Cʲ or *Cj, or the was dropped early on.) The main exception to the lack of yer tensing is in long adjectives, where nominative becomes expected (oj) only when stressed, but yer-tensed (yj) elsewhere, and nominative (which is never stressed) always becomes yer-tensed (ij). Some yers