There was also Old Angarak, but evidently no modern Angarak. The whole reef of Korim/Turim thing in the Mallorean brought up language shift, but that got brushed off, too. And somehow everyone else spoke the same language. The magically learning languages trick is a cop-out, but at least it acknowledges that multiple races spread out across continents and over vast amounts of time would have some differences in language.

Not that the various problems stop me from enjoying the Belgariad and the Mallorean. *g*