Unless I misunderstood his definition, basically a “real language” is one with grammar. Having a history and being subject to change are characteristics of the conlangs he discusses, but aren’t required.
To me that doesn’t make them “real languages” since they’re not the everyday language of any community, but maybe I’m being too nitpicky with my definition. Maybe Klingon, Na’avi, et al should instead be considered, like Latin or Navajo, to be “dead” languages, since they’re only used and spoken by specialists. Except in the case of Klingon, Na’avi, et al they’re really DOA languages, since they didn’t originate as the spoken language of a community, but are more like Esperanto. Except spoken by more people.
