User blog comment:Nomad27/The Illiterate Overlord and Friends/@comment-26501532-20150803083830

Well, at least they can learn from things mentally, such as Cocytus learning to command an army and Ainz learning to fight like a warrior with advises given from Cocytus

So I actually think that Ainz should use some their sages in Nazarick to become teachers to teach some of the residents (especially those with a lot of free time) there to learn some of their langguage so they can help be the translator in times of reading. ( personal idea though)