Different graphical representations of an old phoneme *ě: *ě > h, *ě > і, *ě > е have been fixed in the language of XIV century Ukrainian charters. It is possible to conclude on the partial compliance of the Old Church Slavonic spelling as well as different sound distinctions of the old *ě. The analyses of confusable spelling has shown the significant deviation from traditional writing, in particular, the transformation of *ě into the monophthong і, which was peculiar for the southwestern territory, and became a differential feature of the modern Ukrainian literary language, as well as the tendency for the Polissia-Volyn reflexes of ять, that can be seen in today’s oral folk speech.