A common trope in modern fantasy/science fiction is the idea of a central language (often called The Speech) that is the root of all languages, and in some cases comprises the true describing words that made the universe. Unifying characteristics of this language in many books include:
A popular example of this is found in the Young Wizards series of novels by Diane Duane. All creatures and things understand and, to a degree, can speak the Speech intuitively, but specifically, it is the wizards who use it as their primary language and means of performing their works of magic. It is incredibly detailed and describes things which other languages cannot. Describing something inaccurately in the Speech may result in catastrophic effect (including changing the nature of the thing or being therein mis-described); therefore, wizards are advised to never curse or lie in the Speech. Spells are described in the Speech; the wizard tells the object/subject what he/she wants to happen to it. With a final word, the spell can be let loose to do what it was supposed to do.
The written characters of the Speech have been described in several of the books as resembling written Arabic. In Deep Wizardry, Nita's father mistakes the writing on the title page of Nita's Manual for Arabic letters.
Other examples: