EN
The studies of place names show that the north of Belarus can be divided into the following areas: (1) from the present border of the Republic of Lithuania to the line Pliusy, Zaracha, Delek, and Kazeny, where 90% to 60% of oikonyms of Lithuanian origin can be found; (2) up to Druya, Miory, New Pogosts, and Iody districts inclusive (60%-20% of Lithuanian oikonyms); (3) up to Verkhnedvinsk, Germanovichi, and Glubok districts (5%-1% of Lithuanian oikonyms); (4) up to Obole, Ula, Obolcy, Tolochin, where Lithuanian oikonyms, hydronyms and antroponyms are found; (5) up to Smolensk district in Russia. In the above mentioned areas even in the parts of the same district the number of Lithuanian and Baltic place names is unequal. The bigger concentration of Lithuanian place names shows that more Lithuanians lived there and they lived there for a longer time (districts of Ikazne-Iody, Perebrode, Druya and others). The place name 'kumsa' (Kamsa) in the parish of Ikazne and the harder consonants enable us to draw a conclusion that people there spoke in the same dialect of Vilniskiai up to now spoken 10-20 kilometers to the west and north-west.