East Slavic language spoken in Ukraine and in Ukrainian communities in neighbouring Belarus, Russia, Poland, and Slovakia. Ukrainian is a lineal descendant of the colloquial language used in Kievan Rus (10th–13th century). It is written in a form of the Cyrillic alphabet and is closely related to Russian and Belarusian, from which it was indistinguishable until the 12th or 13th century. Ukrainian resembles Russian less closely than does Belarusian, though all three languages are in part mutually intelligible.

After the fall of Kievan Rus in the 13th century, the dialectal characteristics that distinguish Ukrainian from its sister languages emerged, but for many centuries thereafter the language had almost no literary expression owing to Ukraine's long political subordination. It was not until the end of the 18th century that modern literary Ukrainian emerged out of the colloquial Ukrainian tongue. Like Belarusian, the Ukrainian language contains a large number of words borrowed from Polish, but it has fewer borrowings from Church Slavonic than does Russian.