A Complete Hierarchy of Languages

A complete hierarchy of languages is introduced to defend the thesis that "human language is a Turing complete language". This complete hierarchy discriminates languages on computability, meaning mixability, generativity, decidability, and expressiveness. We show that our thesis is true and, using the complete hierarchy, that our thesis is more specific and then more significant than other truths about human language. The complete hierarchy explains the evolution of language on the assumption that it was driven by expressiveness, and consequently it explains that our language is complete because complete languages are the most expressive languages.