Study of the nature and structure of language.
Linguists use a synchronic (describing a language as it exists at a given time) or a diachronic (tracing a language's development through its history) approach to language study. Greek philosophers in the 5th century BC who debated the origins of human language were the first in the West to be concerned with linguistic theory. The first complete Greek grammar , written by Dionysus Thrax in the 1st century BC, was a model for Roman grammarians, whose work led to the medieval and Renaissance vernacular grammars. With the rise of historical linguistics in the 19th century, linguistics became a science. In the late 19th and early 20th centuries Ferdinand de structuralism ), which analyzed actual speech to learn about the underlying structure of language. In the 1950s Noam Chomsky challenged the structuralist approach, arguing that linguistics should study native speakers' unconscious knowledge of their own language (competence), not their actual production of language (performance), and developed {{link=generative grammar">generative grammar .