Garlemald - Language

[Rosenoire]

Not seeing the language spoken in text is unfortunately poor evidence that the language does not exist. For example, the Xaela of the Steppe continue to speak the old Auri tongue to this day and we only get the odd Mongolian word here and there.

I've actually been wondering about that. Obviously, the WoL has the Echo, so we can understand everyone, but Lyse, Gosetsu, and Hien don't have the Echo, yet they can converse with the Xaela just fine--including the Mol kids. How is that possible?