However, we can make some educated guesses based on the historical context:
* Church Slavonic: This was the liturgical language of the Eastern Orthodox Church, which was the dominant religion in Russia at the time. Ivan the Great would have been familiar with Church Slavonic, even if he didn't speak it fluently.
* Russian: This was the language of his court and the people he ruled. While there were various regional dialects, Ivan the Great likely spoke a form of Old East Slavic, the ancestor of modern Russian.
* Other languages: Depending on his diplomatic dealings, Ivan the Great might have spoken or at least understood other languages, such as Tatar, Lithuanian, or Polish.
It's important to remember that historical figures were often multilingual to some degree, and Ivan the Great's linguistic abilities were likely dictated by his political and religious needs.