This document discusses the properties and characteristics of human language according to two classifications. Francis P. Dinneen identified 9 properties: sound, linear, systematic, meaningful, arbitrary, conventional, creative, unique, and similar to other languages. George Yule identified 6 properties: displacement, arbitrariness, productivity, cultural transmission, discreteness, and duality. It also provides more details on each of Yule's properties, describing how displacement refers to references to past/future/other locations, arbitrariness means there is no natural connection between form and meaning, and productivity means the potential number of utterances is infinite.