Slavs
Slavs are the largest ethno-linguistic group in Europe. Present-day Slavic people are classified into East Slavs (chiefly Belarusians, Russians, Rusyns, and Ukrainians), West Slavs (chiefly Czechs, Kashubs, Moravians, Poles, Silesians, Slovaks and Sorbs), and South Slavs (chiefly Bosniaks, Bulgarians, Croats, Macedonians, Gorani, Pomaks, Montenegrins, Serbs and Slovenes).
North Slavs
According to , Ukrainian shares 70% common vocabulary with Polish, 66% with Slovak, and 62% with Russian. Furthermore, Tyschenko identified 82 grammatical and phonetic features of the Ukrainian tongue – Polish, Czech and Slovak share upwards of 20 of these characteristics with Ukrainian, and 11 are shared with Russian.