This document discusses the formal structure of language. It is composed of at least 8 levels of analysis: 1) phonetics, 2) phonology, 3) morphology, 4) lexicon, 5) syntax, 6) semantics, 7) pragmatics, and 8) discourse. These levels range from the smallest units of sound to larger contexts of meaning and use. Together, they form the complex abstract system that is human language.