It is impossible to separate language from literature, or politics, or most of our everyday human interactions. In this article, though, discussion is centered on language structure rather than how it is used in human society. Accordingly, language is treated almost exclusively from the point of view of linguistics, and the article concentrates on what we have learned about language from that discipline over the last two centuries. Linguists study individual human languages and linguistic behaviour in order to discover the fundamental properties of this general human language. Through this enterprise, they also hope to discover some fundamental aspects of what it means to be human. The importance of language and languages goes far beyond internal structure, extending to almost all human endeavours.
Language, being a human activity, is social in nature; hence, linguistics is usually classified as a social science. Because languages can only be studied through human behaviour, linguistics, like psychology, is further classified as a behavioral science; and because language is essentially mental, linguistics is also a cognitive science.
There are many ways to study language scientifically. The most traditional, with its roots going back thousands of years to the Classical Greek and even Classical Sanskrit grammarians, is called Descriptive Linguistics. Its goal is to provide an explicit description of a language (often called a grammar), either in whole or in part (for example, a description of the sound system of Swahili). A linguist’s grammar, though, unlike those some may remember from school, is never prescriptive: it does not dictate how a language should be (proper language) but instead draws on the actual linguistic behaviour of speakers. Often, a descriptive linguist, especially one working on one of the many less-studied languages, will spend considerable time in the field, learning from the speakers of the language and sometimes writing the language down for the first time. Theoretical Linguistics, of which there are many varieties, seeks to provide explicit general principles that are applicable to all languages, often drawing on descriptive grammars. Within both descriptive and theoretical linguistics, historical linguistics is devoted to the study of how languages change over time. Sociolinguistics treats the broad question of language in society and includes the study of dialects. Psycholinguistics uses the methods of experimental psychology with language as the primary source of data. Child Language Acquisition is devoted to learning how children acquire language early in life. Neurolinguistics addresses the relationship between language and the brain. Computational Linguistics deals with the interaction of computers and language, for such purposes as Speech Synthesis, the production of artificial speech from written text, or Speech Recognition, the conversion of speech to text, or parsing, the automatic description of the grammatical structure of a text.
Written Language and Spoken Language
Most people think of a language as primarily written. Indeed, when a person studies a language in school, they usually study the written language, either literature (texts written in the language) or composition (in which the students compose their own written texts). Spoken language is given second place in schools and universities, except at the very elementary level of foreign language study. What set modern linguistics apart, beginning in the nineteenth century, was the realization that the opposite is true: language is primarily spoken, and written language is an imperfect reflection of spoken language, conveyed through a fairly new and imperfect technology, writing.
The main evidence behind this conclusion is the fact that every human society has a fully functioning spoken language while, until a century ago, only a very few societies had a written language and even then, literacy was, again until recently, confined only to a small class of people. Furthermore, the few writing systems that existed prior to the twentieth century all owed their origins to three or four quite recent inventions, not much more than five thousand years old, while many scholars believe that human language evolved at least 50,000 years ago. All these writing systems arose in early materially advanced state-like societies. These inventions include Sumerian cuneiform and Egyptian hieroglyphic writing in the Middle East (likely related to one another in origin); Chinese writing; and Mayan hieroglyphic writing (deciphered only in the mid twentieth century). The alphabet, the most widely used of modern writing systems, was an adaptation by Semitic-speaking people of aspects of the Egyptian system. It is therefore spoken language that is common to all human societies.
Spoken language comes naturally to all normal human children: expose a normal young human child to any language from a very early age and the child will fully master the language without any overt instruction, while it is very difficult for most humans to acquire a new language after a certain age (generally around puberty). It is as if young human children came preprogramed to acquire a spoken language (something that many though not all linguists believe). Written language, by contrast, must be overtly taught; it is never learned effortlessly, and rarely perfectly.
Language Equality
If all societies have languages, then we may begin to ask in what ways all these languages differ from one another and in what ways they are similar. The first question, asked very early on in the history of the modern study of language, was whether one language is more advanced or evolved or complex than another. The answer is no: there is no obvious way to rank languages on some evolutionary scale: all languages appear to be equal in their expressive capacities. Some languages may have more words than others or may have words for certain notions that are not conventionalized in other languages, but no language is inherently incapable of expressing a given proposition. This realization of the equality of natural languages was in turn important in the realization that all humans are equal, regardless of the material, social, economic, and political complexity of the society in which they live. We know that members of the materially most simple societies are equal to members of the materially most advanced societies in no small part because we can find no convincing evidence that the language of one is more advanced than the language of the other.