Castoquial

Castoquial is considered the common tongue of Paracelsus.
As the native language of Formcaste and their proprietary, the nomadic communities and settlements of the Dust Plains, this language spread as relentlessly as Formcastians themselves once Fragmenterra hit.
Much easier to learn than any of the other languages in Paracelsus, it has quickly become a staple used by almost all citizens of the world.