A natural language is one that has developed spontaneously over time and has had no interference from control or standardization. By this definition, English is not a natural language but the London area dialect from which it sprang in the distant past would have been a natural language, while African American Vernacular English (AAVE) is classed as a natural language. Presently, there are some aboriginal languages, like the Andamanese aboriginal language, that exemplify this definition of natural language: spontaneously developing over time without interference, control or standardization.
Natural language study is a descriptive study of language rather than a prescriptive study, such as grammarians and dictionary writers engage in. Some classifications of principal kinds of meaning that are encoded in natural languages per the definition above are genetic, typological and areal. Encoded genetic meaning identifies the family of languages to which a given natural language is related. This specifies common ancestors of various natural languages, such as the family of Sino-Tibetan languages.
Encoded typological information identifies the internal structure of natural languages in terms of grammar, which reveals the organization of thought through language, in accord with syntactical order of subject, verb and object. Some natural languages may be ordered according to Subject Verb Object (SVO), while others may be ordered according to Object Subject Verb (OSV) or Verb Subject Object (VSO) or other orders. Encoded areal (i.e., pertaining to area) meaning identifies the associations of language-speaking groups in which convergence of language features has occurred giving groups of non-genetically related languages converged, or shared, features.