Here's why:
* Mandinka is the dominant language of the Mandinka people, who are the core ethnic group of the Mali Empire.
* The Epic of Sundiata, the primary source of information about Sundiata's life, is written in a form of Mandinka known as Mandekan.
* Historical context: Mandinka was the language of administration and trade in the region during Sundiata's time.
However, it's important to note that:
* The Epic of Sundiata was not written down until centuries after Sundiata's reign, making it difficult to definitively confirm his language.
* Sundiata's reign saw the rise of a multi-ethnic, multi-lingual empire, suggesting he may have spoken other languages as well, like Songhai or Fulani.
Therefore, while we can confidently say Sundiata likely spoke Mandinka, it's also possible he spoke other languages due to his position and the diversity of his empire.