Here's why:
* Shared Origins: Both Ukrainian and Russian are East Slavic languages, meaning they share a common ancestor, Old East Slavic, which was spoken in Eastern Europe from the 9th to the 14th centuries.
* Mutual Intelligibility: While not entirely mutually intelligible, there is a significant degree of understanding between speakers of Ukrainian and Russian. Many words and grammatical structures are shared, making it possible for speakers of both languages to communicate to some extent.
* Historical Influences: The two languages have been heavily influenced by each other throughout their history. Russian has historically been the dominant language in the region, and its influence can be seen in Ukrainian vocabulary and grammar.
While Russian is the closest language, Belarusian also shares a significant amount of similarity with Ukrainian, owing to their common origins and shared history.
However, it's important to note that Ukrainian has been actively developing its own distinct identity, both linguistically and culturally, particularly in the face of Russian influence.