The official language in the Ukraine is Ukrainian, but the language actually spoken depends on where in the country you are. In the more patriotic west it is Ukrainian that is most commonly used, and Russian will often a provoke a peevish response. The borders of Central and Eastern European countries have moved to and fro with dizzying frequency over the centuries, and up until 1939 Lviv was part of Poland therefore many people speak Polish.
In the east and south of Ukraine it is Russian that dominates. In the capital Kyiv which sits roughly half way across it is half and half. This can be confusing for foreigners trying to learn some of the vocabulary to get by. Which language should one go for? Ukrainian is the official national language, but Russian is commonly used and geographically more widespread. In Lviv they say 'Learn Ukrainian of course!' but in Kyiv, Odessa or the Crimea they will advise you to learn Russian.
