In the 19th century, the Tsarist Government of the Russian Empire claimed that Ukrainian was merely a dialect of Russian and not a language on its own. The differences were few and caused by the conquest of western Ukraine by the Polish-Lithuanian Commonwealth. However, the dialects in Ukraine eventually differed substantially from the dialects in Russia.
The conquest of western Ukraine by what country altered the language of Ukraine?
{'text': 'Polish-Lithuanian Commonwealth', 'answer_start': 230}