Around the tenth century, Russian may have already had paired coronal fricatives and sonorants so that could have contrasted with , but any possible contrasts were limited to specific environments. Otherwise, palatalized consonants appeared allophonically before front vowels. When the yers were lost, the palatalization initially triggered by high vowels remained, creating minimal pairs like ('given') and ('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.