Language

Language is the human capacity for acquiring and using complex systems of communication, and a language is any specific example of such a system. The scientific study of language is called linguistics. It is impossible to know precisely how many languages there are in the world, and the number depends on a partly arbitrary distinction between languages and dialects. However, estimates vary between around 6,000 and 7,000 languages in number. Natural languages are spoken or signed, but any language can be encoded into secondary media using auditory, visual or tactile stimuli, for example in graphic writing, braille, or whistling. This is because human language is modality-independent. When used as a general concept, "language" may refer to the cognitive ability to learn and use systems of complex communication, or to describe the set of rules that makes up these systems, or the set of utterances that can be produced from those rules.

Human language is unique among the lifeforms of Earth because its complex structure affords a much wider range of possible expressions and uses than any known system of animal communication, all of which are generally closed systems, with limited functions and mostly genetically rather than socially transmitted. In contrast to non-human communication forms, human language has the properties of productivity, recursivity, and displacement. Human language is also the only system to rely mostly on social convention and learning. Language is thought to have originated when early hominins first started cooperating, gradually changing their primate communication systems as they acquired the ability to form a theory of other minds and shared intentionality.