Traditional & Cultural Languages in Altwaus

The development of The Common Language is said to have been one of the greatest acts of unity and cooperation ever conducted in Alwaus, The Known World. A collaborative effort between Alvain and Kinderstärke, it took elements from both of their high complex native languages and compiled them into a simple, straight-forward language to would serve as a common means of communication between not just Alvain and Kinderstärke, but eventually all the cultured species of Altwaus. 
Millennia later, the common tongue is spoken in nearly every corner of Altwaus, where it serves as the main language for trade and diplomacy. There are few sentient species that have not taken to the common tongue. 
Despite the presence of the Common Language, there are still many that continue the use of their traditional languages when dealing with their own cultures. Done sometimes because the common language is simply too uncomfortable for their species' vocal physiology to perform, it is more commonly done as an act of cultural preservation. 
In many of the The Thirteen Kingdoms the traditional languages of their respective cultures are taught to the children of the noble class, but not commoners. Albeit it is not uncommon to find particularly remote villages in the various kingdoms that have neglected the common tongue altogether and refuse or prefer not to communicate with anything but their traditional languages. 
Such practices are few and far between, however, and speaking the traditional languages is seen by outsiders as exotic, if not a bit old-fashioned.