From the Appendix of the Dark Series:
The Carpathian language of today is essentially identical to the Carpathian language of thousands of years ago. A "dead" language like the Latin of two thousand years ago has evolved into a significantly different modern language (Italian) because of countless generations of speakers and great historical fluctuations. In contrast, many of the speakers of Carpathian from thousands of years ago are still alive. Their presence which split— coupled with the deliberate isolation of the Carpathians from the other major forces of change in the world— has acted (and continues to act) as a stabilizing force that has preserved the integrity of the language over the centuries. Carpathian culture has also acted as a stabilizing force. For instance, the Ritual Words, the various healing chants, and other cultural artifacts have been passed down the centuries with great fidelity.
One small exception should be noted: the splintering of the Carpathians into separate geographic regions has led to some minor dialectization. However the telepathic links among all Carpathians (as well as each Carpathian's regular return to his or her homeland) has ensured that the differences among dialects are relatively superficial (e.g., small numbers of new words, minor differences in pronunciation, etc.), since the deeper, internal language of mind-forms has remained the same because of continuous use across space and time.
The Carpathian language was (and still is) the proto-language for the Uralic (or Finno-Ugrian) family of languages. Today, the Uralic languages are spoken in northern, eastern and central Europe and in Siberia. More than twenty-three million people in the world speak languages that can trace their ancestry to Carpathian. Magyar or Hungarian (about fourteen million speakers), Finnish (about five million speakers), and Estonian (about one million speakers), arc the three major contemporary descendents of this proto-language.
The only factor that unites the more than twenty languages in the Uralic family is that their ancestry can be traced back to a common proto-language—Carpathian—(starting some six thousand years ago) into the various languages in the Uralic family. In the same way, European languages such as English and French, belong to the better-known Indo-European family and also evolve from a common proto-language ancestor (a different one from Carpathian).