Names in the Ancient Language were ' true names' and the knowledge of such a title was a source of power and control. However it's possible to say something that is not true in the ancient language, if the person speaking it believes it to be true (Murtagh swore to Eragon that they were both Morzan's sons, because he had no knowledge of their mother's affair with Brom). Because of the candid nature of the language, oaths of allegiance and similar contracts were usually conducted in it, ensuring they would not be broken, though they could be twisted to be ineffective if the one who made the oath left enough loopholes in their wording. It was impossible to lie in the Ancient Language because words spoken in the language were unquestionably true-although, it was said that the elves were masters at saying one thing and meaning another (for example, Eragon said he was well in Eldest after Arya's rejection meaning her rejection but focusing on his back to make it true). For example, if a magician cast non-verbally, for example 'Burn that door', and focused on something other than the door, they may accidentally burn that instead.

It was also possible for experienced magicians to utilize Non-verbal manipulation, although this was extremely dangerous, if the mind wandered the spell would change. Each act of magic was linked to a specific word: therefore, it was generally true that the more knowledge one had of the Ancient Language, the more magic they could perform. It was used to command and regulate magic. After a tragic incident which killed most of the beings in Alagaësia, they managed to tie their language with magic through unknown means. It was the language of the Grey Folk, beings who had settled in Alagaësia after dwarves and dragons, those who were native to the land, they settled where the elves and humans would live a few centuries later. The Ancient Language was once a language of all beings in Alagaësia, but was later used only by the elves and some humans, along with the dwarves with one moment being the crowning of their king.