by The Comrade » Mon Jan 06, 2014 1:09 pm
Since its invention in 1269, the 'Phags-pa script, a unified script for spelling Mongolian' Tibetan, and Chinese languages, was preserved in the court until the end of the Dynasty. Most of the Emperors could not master written Chinese, but they could generally converse well in the language.
i would imagine they still used chinese for most of their domestic issues considering the entire kingdom spoke chinese and not everyone in power was a mongol.