There is no reason to treat fictional language in a totally different way.
Slovetzian, a fictional Slavic language, is spoken by the children of the president and other characters in the film.
Novistrana has its own national anthem, which is sung in a fictional language.
Thus, a naturalistic fictional language tends to be more difficult and complex.
It is one of the many fictional languages set in Middle-earth.
It is one of the many fictional languages set in his secondary world, often called Middle-earth.
Andy, however, points out that it is a fictional language, leaving Erin dejected.
Regardless, the oath has only been rendered in the aforementioned fictional language.
Her voice is a fictional language of Hyrule, and thus unintelligible.
Ico uses minimal dialog in a fictional language to provide the story throughout the game.