"An Introduction to Language" by Victoria Fromkin and Robert Rodman states this about speaking: "We are all intimately familiar with a language, our own. Yet, few of us ever stop to consider what we know when we know a language."
Where linguists are concerned, according to Fromkin and Rodman, the analysis of spoken languages dates to at least 1600 B.C. in Mesopotamia. Linguists continue to study verbal language communication based on what is known. Examples of what is known include: wherever humans exist, language exists, all grammars contain rules for the formation of words and sentences, and all languages utilize a finite set of discrete sounds.
Verbal language communication relates sounds with meanings. When learning to communicate verbally, the meanings and rules of a language must be known. According to Fromkin and Rodman, "Speakers use a finite set of rules to produce and understand an infinite set of possible sentences."