This article deals with the factors which cause the human language to be diverse. The study of linguistic literature shows that linguists are much more interested in studying both universality and diversity characteristics of the human language which are of paramount importance from theoretical, practical and linguo-cultural point of view. Thus, the common and specific characteristics of the human language, to our mind, become the major aim and basis of linguistic theory of today. As D.Crystal writes: ?Why study languages?? or Why study language? Perhaps it ought to have been ?language?. For once again I must emphasize that the main task of the linguistic scholar is not to improve the language teaching situation?.. etc.: his task is basically to study and understand the general principles upon which all languages are built. What are the ?design features? of human language? This is his prime concern. How far can we define the universal characteristics of language? Or, putting this another way, ?What are the differences between languages? How can we describe and classify these? and How far are they fundamental? What concepts do we have to develop before we can begin to talk about language at all?.(D.Crystal, 1977). In this respect we hope that this article may throw some light on the questions mentioned above. Our aim, accordingly, is to study the diversity of human language and to discover the natural factors which cause the human language to have different structures and properties.