Dwarven, or Dwarvish, is the primary language of the Dwarves. Dwarves originally did not have a written language, instead passing their knowledge down through oral tradition. Humans taught dwarves how to write in Common, which was much simpler and easier than runes; and over the years, the dwarves altered the language into their own design. Dwarven looks like a weird hybrid of Titan glyphs and human letters. (APG 140) In World of Warcraft, the Dwarven language is listed as Dwarven under the Dwarf skill list, and Dwarvish in chat mode.[citation needed]