The Klingon Dictionary,which is copyrighted by Paramount Pictures,has sold more than 300,000 copies, and has made quite a bit of money for Paramount Pictures.Unlike Esperanto,Kligon is an extremely complicated language with a complex grammar,making it an immensely difficult language to learn. As a result,it is estimated that only a few thousand people can speak Kligon with any fluency. Yet interestingly,Okrand intentionally made Klingon difficult to learn. His goal for Klingon was almost the opposite of Zamenhof's goal for Esperanto. Olrand did not want many people to be able to speak Klingon fluently. On the contrary,Klingon was designed to bo an exclusive language that could only be spoken by the most committed Star Trek fans.