('tribute'). At the same time, , which was already a part of the vocalic system, was reanalyzed as an allophone of after hard consonants, prompting leveling that caused vowels to alternate according to the preceding consonant rather than vice versa. Sometime between the twelfth and fourteenth centuries, the velars became allophonically palatalized before , which caused its pronunciation to change from to . This is reflected in spelling, which writes e.g. (gíbkij) rather than (gybkyj). Depalatalization The palatalized unpaired consonants depalatalized at some point, with becoming retroflex and . This did not happen, however, to , which remains to this day as palatalized . Similarly did not depalatalize, becoming (formerly and still occasionally ). The depalatalization of is largely not reflected in spelling, which still writes e.g. (šitʹ), rather than (šytʹ), despite the pronunciation . Paired palatalized consonants other than and sometimes and eventually lost their palatalization when followed by another consonant. This is generally reflected in spelling. Examples: Proto-Slavic "to stick" > Russian (lʹnutʹ) Proto-Slavic "sun" > Russian (sólnce) Proto-Slavic "ox-yoke" > Russian (jarmó); but Proto-Slavic "bitter" > Russian (gorʹkij) Proto-Slavic "ancient" > Russian (drévnij) Proto-Slavic "cowberry" >> Russian (brusníka) Incomplete early palatalizations There is a tendency to maintain intermediate ancient , , etc. before frontal vowels, in contrast to other Slavic languages. This is the so-called incomplete second and third palatalizations: Ukrainian Russian: ('leg' dat.) It is debated whether these palatalizations never occurred in these cases or were due to later analogical developments. A relevant data point in this respect is the Old Novgorod dialect, where the second palatalization is not reflected in spelling and may never have happened. Development of palatal consonants The Proto-Slavic palatal series of consonants (not to be confused with the later palatalized consonants that developed in Russian) developed as follows: The palatal resonants merged with the new palatalized consonants *lʲ *nʲ *rʲ that developed before Proto-Slavic front vowels. The palatal plosives merged with . Note, however, that Proto-Slavic appear as (commonly notated šč žd and pronounced respectively, although was formerly pronounced , as its transcription suggests) in words borrowed from Old Church Slavonic. The palatal clusters developed into sounds denoted respectively and either or (nowadays normatively pronounced , although there is a strong tendency to instead pronounce and as hard ). The palatal fricatives hardened into retroflex (although the affricate remained as soft ). Degemination Many double consonants have become degeminated but are