Language

A language is a system of symbols, generally known as lexemes and the grammars (rules) by which they are manipulated. The word language is also used to refer to the whole phenomenon of language, i.e., the common properties of languages. Language is commonly used for communication, though it has other uses.

Language is a natural phenomenon, and language learning is common in childhood. In their usual form, human languages use patterns of sound or gesture for the symbols in order to communicate with others through the senses. Though there are thousands of human languages, they all share a number of properties from which there are no known deviations. There is no defined line between a language and a dialect, but it is often said that a language is a dialect with an army and a navy.

Humans have also constructed other languages, including Esperanto and Klingon, programming languages, and various mathematical formalisms. These languages are not necessarily restricted to the properties shared by natural human languages.



Properties of language
Languages are not just sets of symbols. They also contain a grammar, or system of rules, used to manipulate the symbols. While a set of symbols may be used for expression or communication, it is primitive and relatively unexpressive, because there are no clear or regular relationships between the symbols. Because a language also has a grammar, it can manipulate its symbols to express clear and regular relationships between them.

For example, imagine going on a walk with a person who only knew individual symbols, or words. If you saw a dog, he might say, "Dog scare" or "Scare Dog". Although any English speaker would have some notion of what he was talking about, the relationship between the words is unclear. Is he scared of dogs? Or just that dog? Or does he want to scare the dog off? Does he think the dog is scared? But if you respond, "I’m not scared of dogs," the relationship between dog and scare is quite apparent and hence the meaning of the utterance.

Another important property of language is the arbitrariness of the symbols. Any symbol can be mapped onto any concept (or even onto one of the rules of the grammar). For instance, there is nothing about the Spanish word nada itself that forces Spanish speakers to use it to mean nothing. That is the meaning all Spanish speakers have memorized for that sound pattern. But for Croatian speakers nada means hope.

However, it must be understood that just because in principle the symbols are arbitrary does not mean that a language cannot have symbols that are iconic of what they stand for. Words such as meow sound similar to what they represent, but they could be replaced with words such as jarn, and as long as everyone memorized the new word, the same concepts could be expressed with it.

Human languages
Human languages are usually referred to as natural languages, and the science studying them is linguistics.

Making a principled distinction between one language and another is usually impossible. For example, the boundaries between named language groups are in effect arbitrary due to blending between populations (the dialect continuum). For instance, there are a few dialects of German similar to some dialects Dutch.

Some like to make parallels with biology, where it is not always possible to make a well-defined distinction between one species and the next. In either case, the ultimate difficulty may stem from the interactions between languages and populations. (See Dialect or August Schleicher for a longer discussion.)

The concepts of Ausbausprache, Abstandsprache, and Dachsprache are used to make finer distinctions about the degrees of difference between languages or dialects.

Origins of human language
Scientists do not yet agree on when language was first used by humans (or their ancestors). Estimates range from about two million (2,000,000) years ago, during the time of Homo habilis, to as recently as forty thousand (40,000) years ago, during the time of Cro-Magnon man. The nature of speech means that there is almost no data on which to base conclusions on the subject.

Language taxonomy
The classification of natural languages can be performed on the basis of different underlying principles (different closeness notions, respecting different properties and relations between languages); important directions of present classifications are:
 * paying attention to the historical evolution of languages results in a genetic classification of languages&mdash;which is based on genetic relatedness of languages,
 * paying attention to the internal structure of languages (grammar) results in a typological classification of languages&mdash;which is based on similarity of one or more components of the language’s grammar across languages,
 * and respecting geographical closeness and contacts between language-speaking communities results in areal groupings of languages.

The different classifications do not match each other and are not expected to, but the correlation between them is an important point for many linguistic research works. (There is a parallel to the classification of species in biological phylogenetics here: consider monophyletic vs. polyphyletic groups of species.)

The task of genetic classification belongs to the field of historical-comparative linguistics, of typological&mdash;to linguistic typology.

See also: Taxonomy, Taxonomic classification&mdash;for the general idea of classification and taxonomies.

Genetic classification
The world’s languages have been grouped into families of languages that are believed to have common ancestors. Some of the major families are the Indo-European languages, the Afro-Asiatic languages, the Austronesian languages, and the Sino-Tibetan languages.

The shared features of languages from one family can be due to shared ancestry. (Compare with homology in biology.)

Typological classification
An example of a typological classification is the classification of languages on the basis of the basic order of the verb, the subject and the object in a sentence into several types: SVO, SOV, VSO, and so on, languages. (English, for instance, belongs to the SVO language type.)

The shared features of languages of one type (= from one typological class) may have arisen completely independently. (Compare with analogy in biology.) Their cooccurence might be due to the universal laws governing the structure of natural languages&mdash;language universals.

Areal classification
The following language groupings can serve as some linguistically significant examples of areal linguistic units, or sprachbunds: Balkan linguistic union, or the bigger group of European languages; Caucasian languages. Although the members of each group are not closely genetically related, there is a reason for them to share similar features, namely: their speakers have been in contact for a long time within a common community and the languages converged in the course of the history. These are called ''areal features.

NB. One should be careful about the underlying classification principle for groups of languages which have apparently a geographical name: besides areal linguistic units, the taxa of the genetic classification (language families) are often given names which themselves or parts of which refer to geographical areas.

Constructed languages
The study of natural languages has prompted many individuals to construct their own artificial languages, for practical, experimental, or ideological reasons. For example, one prominent artificial language, Esperanto, was created by L. L. Zamenhof as a compilation of various elements of different languages, and it is intended to be an easy-to-learn language. Other constructed languages strive to be more logical than natural languages; a prominent example of this is Lojban.

Some writers, such as J. R. R. Tolkien, and Christopher Paolini, have created fantasy languages, for literary, artistic, or personal reasons. One of Tolkien’s languages is called Quenya. It has its own alphabet, and its phonology and syntax are modelled on Finnish, and forms part of a whole system of languages invented by the linguist. The main fantasy language created by Paolini is the ancient language. This comprises of many grammar and vocabulary similarities between Old Norse, and other mainly unused languages. The usage of this language is mainly either to define which form of magic is wished to be used, or as the main language used by the magical elves.

The study of language
The oldest surviving written grammar for any language is believed to be the Tolkāppiyam (தொல்காப்பியம்), a book on the grammar of the Tamil language, written around 200 BC by Tolkāppiyar. Its classification of the alphabet into consonants and vowel was a breakthrough. The historical record of the study of language begins in North India with Pāṇini, the 5th century BC grammarian who formulated 3,959 rules of Sanskrit morphology, known as the  (अष्टाध्यायी). grammar is highly systematized and technical. Inherent in its analytic approach are the concepts of the phoneme, the morpheme, and the root; the phoneme was only recognized by Western linguists some two millennia later.

In the Middle East, the Persian linguist Sibawayh made a detailed and professional description of Arabic in 760 CE in his monumental work, Al-kitab fi an-nahw (الكتاب في النحو, The Book on Grammar), bringing many linguistic aspects of language to light. In his book he distinguished phonetics from phonology.

Later in the West, the success of science, mathematics, and other formal systems in the 20th century led many to attempt a formalization of the study of language as a "semantic code". This resulted in the academic discipline of linguistics, the founding of which is attributed to Ferdinand de Saussure.

Animal (nonhuman) language
While the term animal languages is widely used, most researchers agree that they are not as complex or expressive as human language; a more accurate term is animal communication. Some researchers argue that there are significant differences separating human language from the communication of other animals, and that the underlying principles are not related.

In several widely publicised instances, animals have been trained to mimic certain features of human language. For example, chimpanzees and gorillas have been taught hand signs based on American Sign Language; however, they have never been taught its grammar. There was also a case in 2003 of Kanzi, a captive bonobo chimpanzee allegedly independently creating some words to mean certain concepts. While animal communication has debated levels of semantics, it has not been shown to have syntax in the sense that human languages do.

Some researchers argue that a continuum exists among the communication methods of all social animals, pointing to the fundamental requirements of group behaviour and the existence of "mirror cells" in primates. This, however, may not be a scientific question, but is perhaps more one of definition. What exactly is the definition of the word "language"? Most researchers agree that, although human and more primitive languages have analogous features, they are not homologous.

Formal languages
Mathematics and computer science use artificial entities called formal languages (including programming languages and markup languages, but also some that are far more theoretical in nature). These often take the form of character strings, produced by some combination of formal grammar and semantics of arbitrary complexity.