Natural Language

AKA: Human Language System.
Context:
- It can (typically) be used by a Linguistic Agent to communicate meaning (to another linguistic agent).
- It can (typically) be restricted to Linguistic Expressions that satisfy a Natural Language Syntax and have a Grammatical Mood, Grammatical Tense, Grammatical Aspect, Grammatical Polarity.
- It can contain an Infinite Set of Natural Language Words.
  - Composed of an Infinite Set of Content Words and a Finite set of Function Words.
  - Associate to a Lexicon (of Lexemes??).
- It can evolve and have Dialects.
- It can range from being a Spoken Language to being a Written Language (supported by a writing system).
- It can be Modeled by a Natural Language Theory.
- It can belong to a Natural Language Group.
Example(s):
- an Evolved Natural Language.
  - English Language (English, American, Canadian, Australian, Indian).
  - Spanish Language (Spain, Mexico, Argentinian).
  - Chinese Language.
  - German Language.
  - Finnish Language.
  - Swiss-German Language.
  - Bambara Language.
  - Greek Language.
- a Constructed Natural Language, such as Esperanto or Structured English.
- …
Counter-Example(s):
- an Artificial Language.
See: Natural Language Processing, Formal Language.

References

WordNet.
- a human written or spoken language used by a community; opposed to e.g. a computer language
http://en.wiktionary.org/wiki/natural_language
- a human language which has evolved naturally in a community, usually in contrast to computer programming languages or to artificially constructed ...
CYC Glossary http://www.cyc.com/cycdoc/ref/glossary.html
- natural language (NL): Natural language is just human language, for example English. When people talk about "NL" aspects of CYC®, they are referring to Cyc's growing ability to understand natural language.

(ANSI Z39.19, 2005) ⇒ ANSI. (2005). “ANSI/NISO Z39.19 - Guidelines for the Construction, Format, and Management of Monolingual Controlled Vocabularies." ANSI.
- QUOTE: "natural language A language used by human beings for verbal communication. Words extracted from natural language texts for indexing purposes without vocabulary control are often called keywords.