I absolutely agree with paulb's post. For about 50% Ukrainians Russian is a native language. And for the large part of another half who count Ukrainian as a native tongue (my wife is one of them), this Ukrainian isn't the same language. Ukrainian spoken in Lvov region and in Chernigov region are very different and both differ from Ukrainian wich is spoken on Ukrainian TV and radio. The first one use many Polish words and the second one use many Russian words instead of 'standart' Ukrainian.
In XVI-XVII centuries some parts of modern Ukraine, Belarus, Lithuania and Russia belonged to Polish-Lithuanian commonwealth (so-called Rzeczpospolita Obojga Narodów (in Polish) or Republic of Both Nations). Many Poles still think that Russia 'illegaly occupied' these lands.Originally Posted by Hanna