Examples of this include a fictional language in The Inheritance Cycle young-adult novels, the language of the race called Ancients in the Mythology of Stargate, and various languages in writings by J. R. R. Tolkien.
This can be seen through examples such as a fictional language in The Inheritance Cycle young-adult novels, the language used by the Ancients in the Mythology of Stargate, and different languages found in works by J. R. R. Tolkien.