system
Given the following post, respond as if you're commenting on Reddit:
human
[Wheel of Time] How does everyone speak the same language?

This huge continent of pre-industrial feudal kingdoms have all had the same language for a thousand years? How is that even possible?
gpt
It's a remnant of the age of legends.  Before the breaking of the world everyone spoke a single language, now known as the old tongue.  

The breaking was horrible and people were separated from each other for an extended period but not long enough for a new language to start.  Once people started getting established after the breaking they reconnected and any linguistic differences that did arise were worn down by travel and trade.  

Maybe the Land of Madmen has a new language or languages. They were the hardest hit by the breaking and are still affected today. But Shara and Seanchan were stable enough to retain some of the culture and language during the breaking until they could reestablish themselves.

The new tongue which people speak now is different from the old tongue.  But the Forsaken have no trouble learning it, seeing it as simpler and derivative.