From ThresholdRPG Wiki

Languages are prolific in the world of Primordiax on which the game of Threshold occurs. While most speak the common tongue, each of the civilized races speak their own racial language as well. But the power of language is not the sole province of the civilized as many of the more intelligent and organized racial foes of the kingdoms have their own languages as in the case of the orcs, goblins and others.

Some spells and artifacts in-game provide the ability to not only understand other languages than your own, but, also speak them.