Natural language

Natural language means human speech, sign language and writing, as they have developed as means of communication for the human species. This contrasts with artificial languages, which are deliberately invented for a purpose. The science of studying language and specific languages - natural or otherwise - is known as linguistics, but this is not the only field that involves looking at how language works or is used.. The discovery of the oldest evidence of language, primarily via vestiges of early writing, falls under the purview of archaeology and also history. The mechanisms related to learning of natural languages may be of interest in psychology and neuroscience due to its exercise of higher brain function. Computer scientists have been engaged in the study of natural languages for the purpose of machine translation between different languages.

Properties of natural languages

Linguistic scholars have described natural languages as a system of symbols (sometimes known as lexemes) and the grammar (rules) by which the symbols are manipulated. The assignment of meaning to a symbol in a language is arbitrary. 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 accepted for that sound sequence. For Croatian speakers, however, nada means 'hope'. Not all mappings of symbols to concepts are entirely arbitrary, though; speakers may assign meaning to symbols because the spoken sound is imitative of a natural phenomenon. For example, the word 'meow' sounds similar to what it represents (see onomatopoeia).

Language versus dialect classification

From the point of view of historical and comparative linguistics, two natural languages with noticeable differences in pronunciation but which are still 'mutually intelligible', i.e. a speaker of either understands the other, may be classified as being two dialects of the same language. However, the decision to term a particular regional language as its own language, versus a dialect of another language, is sometimes also the result of political divisions, cultural differences, distinctive writing systems, or other factors. Max Weinreich is credited as saying that "a language is a dialect with an army and a navy". For instance, some dialects of German are mutually intelligible with some dialects of Dutch. The transition between languages within the same language family is usually gradual (see dialect continuum). The concepts of Ausbausprache, Abstandsprache and Dachsprache are used to make finer distinctions about the degrees of difference between languages or dialects.

Study of grammar

See also: History of linguistics

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 Aṣṭādhyāyī (अष्टाध्यायी). Pāṇini’s grammar is highly systematized and technical. Inherent in its analytic approach are the concepts of the phoneme, the morpheme, and the root.

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 al-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 twentieth century led many to attempt a formalization of the study of language as a "semantic code". This eventually resulted in the academic discipline of modern linguistics, for which some founding principles were attributed to Ferdinand de Saussure.

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 - which is based on genetic relatedness of languages;
• paying attention to the internal structure of languages (grammar) results in a typological classification of languages - 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 - to linguistic typology.

Genetic classification

See also: Comparative linguistics

The world's languages have been grouped into families of languages that are accepted as having 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 co-occurrence might be due to the universal laws governing the structure of natural languages - 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.

N.B.: 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.

References

• Li G, Wang J, Rossiter SJ, Jones G & Zhang S (2007) 'Accelerated FoxP2 Evolution in Echolocating Bats'. PLoS ONE 2(9): e900. DOI: 10.1371/journal.pone.0000900.