Elemental

Elemental--one of the Six Eternal Languages--is more of a group of languages (one for each element of air, earth, fire, and water) than a single tongue. If desired, native speakers of different elements can make themselves understood in the common tongue, but can also remain incomprehensible. Each sub-language has its own particular flavor of sounds when spoken, corresponding to the element: Auri (air) sounds like whistling or rushing wind; Ore'ach (earth) resembles tumbling or grinding stones; Kreph (fire) mimics flame when soft, explosions when harsh; Undinese (water) recalls a trickling stream to crashing waves.
Elemental is rarely written on paper, but rather in the element it represents. Although the scripts differ by element, all four forms use a similar version of the Elemental Script.