fictional language - A model language intended to be used by characters in a fictional setting, typically for added verisimilitude and regardless of whether the fictional setting has been highly commercialized or barely outlined, whether the medium is a movie, a novel, a short story, a historical sketch, a game or something else.

fictional diachronic language - A model language with an elaborate fictional history, typically tracing its evolution from an ancestor language or language family (which may be a natural language or model language).

fictional naming language - A fictional language developed primarily to have a way to name the people, places and things of an imaginary world and therefore typically consisting of just a hundred or so words of vocabulary, with little or no grammatical details.

international auxiliary language- A model language intended as a lingua franca that will be easy for citizens of different countries to learn. An auxiliary language can be intended for worldwide use or for use within a region (typically Europe).

logical language - A model language intended to remove as much ambiguity (typically syntactical ambiguity) as possible from human communication.

model language - An invented language intended primarily for humans or fictional sentient beings to converse with others of their kind.

personal language - A model language intended for personal amusement or edification.

philosophical language - A model language intended as international auxiliary language, but with a schematic vocabulary, with the initial letters of the word indicating its place in a semantic hierarchy; in other words, the vocabulary is a priori rather than borrowing actual terms from other languages.

stealth language - A model language intended primarily for secret communications with others or oneself (through a journal).

a system of classifying constructed languages

created by Richard K. Harrison, 1 July 1996
revised 1 March 1998
this page is in the public domain
 

People who collect information about planned languages sometimes need a quick way to describe them. I designed this system for use when the usual terms (such as a priori, philosophical, etc) are too long-winded or not specific enough.

This system classifies a language strictly on the basis of one criterion: the source of the majority of words in the vocabulary. Granted, there is a lot more to a language design than that one factor, but it seemed like a reasonable hook on which to hang a system of classification.

• 1. a posteriori
  • 1.1 modified or revived single natural languages
    • 1.1.1 Latin
    • 1.1.2 Modern English
    • 1.1.9 others
  • 1.2 modifications of single a posteriori artificial languages
    • 1.2.1 Esperanto reform projects
    • 1.2.9 others
  • 1.3 combinations of closely-related artificial languages
  • 1.4 blends of closely-related natural languages
    • 1.4.1 pan-(Indo-)European vocabularies
      • 1.4.1.1 Romance vocabularies
      • 1.4.1.2 Germanic vocabularies
      • 1.4.1.3 Romance-Germanic mixtures
      • 1.4.1.4 Slavic vocabularies
      • 1.4.1.9 other
    • 1.4.2 Uralic vocabularies
    • 1.4.3 Sino-Tibetan vocabularies
    • 1.4.4 Afro-Asiatic (Hamitic-Semitic) vocabularies
    • 1.4.5 Niger-Kordofanian and Nilo-Saharan vocabularies
    • 1.4.9 other
  • 1.5 combinations of heterogenous natural languages
    • 1.5.1 words essentially unaltered
    • 1.5.2 words filtered or modified by phonotactic/morphological rules

• 2. a priori and mixed type
  • 2.1 speakable languages
    • 2.1.1 philosophical languages (categorical vocabularies)
    • 2.1.2 a priori but non-categorical vocabularies
    • 2.1.3 mixed type (a priori-a posteriori) vocabularies
  • 2.2 unspeakable projects
    • 2.2.1 pasigraphies (symbol/icon languages)
    • 2.2.2 number languages
    • 2.2.3 pasimologies (gesture languages)
    • 2.2.9 others

Here are examples of how the system categorizes some well-known constructed languages:
1.1.1 Latino sine Flexion [Peano]
1.1.2 Basic English [Ogden]
1.2.1 Ido
1.4.1 Esperanto [Zamenhof]
1.4.1.1 Interlingua [Gode]
2.1.1 Ro [Foster]
2.2.1 Blissymbols