Variation is a characteristic of language: there is more than one way of saying the same thing in a given language. Variation can exist in domains such as pronunciation (e.g., more than one way of pronouncing the same phoneme or the same word), lexicon (e.g., multiple words with the same meaning), grammar (e.g., different syntactic constructions expressing the same grammatical function), and other features. Different communities or individuals speaking the same language may differ from each other in their choices of which of the available linguistic features to use, and how often (inter-speaker variation), and the same speaker may make different choices on different occasions (intra-speaker variation).
While diversity of variation exists, there are also some general boundaries on variation. For instance, speakers across distinct dialects of a language tend to preserve the same word order or fit new sounds into the language's established inventory of phonemes (the study of such restrictions known as phonotactics, morphotactics, etc.); however, exceptions to these restrictions are possible too. Linguistic variation does not equate to ungrammatical usage of the language, but speakers are still (often unconsciously) sensitive to what is and is not possible in their native lect.
Language variation is a core concept in sociolinguistics. Sociolinguists investigate how linguistic variation can be influenced by differences in the social characteristics and circumstances of the speakers using the language, but also investigate whether elements of the surrounding linguistic context promote or inhibit the usage of certain structures.
Variation is an essential component of language change. This is because language change is gradual; a language does not shift from one state to another instantaneously, but old and new linguistic features coexist for a period of time in variation with each other, as new variants gradually increase in frequency and old variants decline. Variationists therefore study language change by observing variation while a change is in progress. However, not all variation is involved in change; it is possible for competing ways of "saying the same thing" to coexist with each other in "stable variation" for an extended period of time.
Studies of language variation and its correlation with sociological categories, such as William Labov's 1963 paper "The social motivation of a sound change," led to the foundation of sociolinguistics as a subfield of linguistics. Although contemporary sociolinguistics includes other topics, language variation and change remains an important issue at the heart of the field.
Sociolinguistic variables Studies in the field of sociolinguistics typically take a sample population and interview them, assessing the realisation of certain sociolinguistic variables. Labov specifies the ideal sociolinguistic variable to be high in frequency, have a certain immunity from conscious suppression, be an integral part of larger structures, and be easily quantified on a linear scale.Labov, William. 1966 . The Social Stratification of English in New York City. Washington, DC: Center for Applied Linguistics. Second edition at . Phonetic variables tend to meet these criteria and are often used, as are morphosyntactic variables, morphophonological variables, and, more rarely, lexical variables. Examples for phonetic variables are: the frequency of the glottal stop, the height or backness of a vowel or the realisation of word-endings. An example of a morphosyntactic variable is the frequency of negative concord (known colloquially as a double negative). Two well-known and frequently studied morphophonological variables are T/D deletion, the optional deletion of the sound /t/ or /d/ at the end of a word, as in "I kep' walking" (Wolfram 1969;Wolfram, Walt. 1969. A Sociolinguistic Description of Detroit Negro Speech. Washington, DC: Center for Applied Linguistics. Labov et al. 1968Labov, William, Cohen, Paul, Robins, Clarence, & Lewis, John. 1968. A Study of the Non-standard English of Negro and Puerto Rican Speakers in New York City. Co-operative Research Report 3288, Vol. 1. Philadelphia: U.S. Regional Survey.); and the ING variable, the optional pronunciation of -ing at the end of a word as -in''', as in "I kept walkin'" (e.g. Fisher 1958; Labov 1966/1982; Trudgill 1974Trudgill, Peter. 1974. The social differentiation of English in Norwich. Cambridge: Cambridge University Press.).
Analysis and methodology Analyzing sociolinguistic variation often involves the use of statistical programs to handle its multi-variable nature. One essential part of the methodology is to count up the number of tokens of a particular variant and compare it to the number of times the variant could have occurred. This is called the "Principle of Accountability" in Tagliamonte (2012). Comparing the tokens to the total number of words in a corpus or comparing one corpus to another leads to erroneous results.Tagliamonte, Sali A. (2012). Variationist Sociolinguistics: Change, observation, interpretation. UK: Wiley-Blackwell. This count of the possible occurrences can be difficult at times because some variants alternate with zero (such as relative pronouns that, who, and zero).
In 1970 Eugenio Coșeriu, revisiting De Saussure's synchrony and diachrony distinction in the description of language, coined the terms diatopic (place-related dialect), diastratic (social class/stratum related sociolect) and diaphasic (formality-related register) to describe linguistic variation.Kastovsky, D. and Mettinger A. (eds.) (2011) The History of English in a Social Context: A Contribution to Historical Sociolinguistics, Introduction, p.xiii Eugenio Coșeriu (1970) Einführung in die strukturelle Betrachtung des WortschatzesHarr, A. K. (2012) Language-Specific Factors in First Language Acquisition: The Expression of Motion Events in French and German, p.12 In 1985, Peter Koch and Wulf Oesterreicher expanded this system to include diamesic variation, which describes linguistic variation based on oral and written conceptions of language.
Association with age There are several different types of age-based variation one may see within a population. They are: vernacular of a subgroup with membership typically characterized by a specific age range, age-graded variation, and indications of linguistic change in progress.
One example of subgroup vernacular is the speech of street youth. Just as street youth dress differently from the "norm", they also often have their own "language". The reasons for this are the following: (1) To enhance their own cultural identity (2) To identify with each other, (3) To exclude others, and (4) To invoke feelings of fear or admiration from the outside world. Strictly speaking, this is not truly age-based, since it does not apply to all individuals of that age bracket within the community. Age-graded variation is a stable variation which varies within a population based on age. That is, speakers of a particular age will use a specific linguistic form in successive generations. This is relatively rare. J.K. Chambers cites an example from southern Ontario, Canada where the name of the letter 'Z' varies.Chambers, J.K. (1995). Sociolinguistic Theory, Oxford: Blackwell. Most of the English-speaking world pronounces it 'zed'; however, in the United States, it is pronounced 'zee'. A linguistic survey found that in 1979 two-thirds of the 12-year-olds in Toronto ended the recitation of the alphabet with the letter 'zee' where only 8% of the adults did so. Then in 1991, (when those 12-year-olds were in their mid-20s) a survey showed only 39% of the 20- to 25-year-olds used 'zee'. In fact, the survey showed that only 12% of those over 30 used the form 'zee'. This is hypothesized to be tied to an American children's song frequently used to teach the alphabet. In this song, the rhyme scheme matches the letter Z with V 'vee', prompting the use of the American pronunciation. As the individual grows older, this marked form 'zee' is dropped in favor of the standard form 'zed'.
People tend to use linguistic forms that were prevalent when they reached adulthood. So, in the case of linguistic change in progress, one would expect to see variation over a broader range of ages. William Bright provides an example taken from American English, where in certain parts of the country there is an ongoing merger of the vowel sounds in such pairs of words as 'caught' and 'cot'.Bright, William (1997). "Social Factors in Language Change." In Coulmas, Florian (ed) The Handbook of Sociolinguistics. Oxford: Blackwell. This merger used to be distinctive of the western United States, but since World War II, it has developed independently in two other regions: western Pennsylvania and southwestward, and the New England coast from Boston north.University of Pennsylvania. circa 2005. Phonological atlas of North America, Map 1. Examining the speech across several generations of a single family, one would find the grandparents' generation would never or rarely merge these two vowel sounds; their children's generation may on occasion, particularly in quick or informal speech; while their grandchildren's generation would merge these two vowels uniformly. This is the basis of the apparent-time hypothesis where age-based variation is taken as an indication of linguistic change in progress.
Association with geography
A commonly studied source of variation is regional dialects (regiolects). Dialectology studies variations in language based primarily on geographic distribution and their associated features. Sociolinguists concerned with grammatical and phonological features that correspond to regional areas are often called dialectologists.
In 1968, John J. Gumperz conducted a survey on the inter-influence of geographic and social factors. By the end of the 1960s, it was examined that linguistic and dialect diversity cannot be solely interpreted by geography, which social differences existed in the same geographical area. Thus, social and geographical factors were to be seen as interrelated.
Association with gender
Men and women, on average, tend to use slightly different language styles. These differences tend to be quantitative rather than qualitative. That is, to say that women use a particular speaking style more than men do is akin to saying that men are taller than women (i.e., men are on average taller than women, but some women are taller than some men).
The initial identification of a women's register was by Robin Lakoff in 1975, who argued that the style of language served to maintain women's (inferior) role in society ("female deficit approach"). A later refinement of this argument was that gender differences in language reflected a power difference ("dominance theory").O’Barr, William and Bowman Atkins. (1980) "'Women’s Language' or 'powerless language'?" In McConnell-Ginet et al. (eds) Women and languages in Literature and Society. pp. 93-110. New York: Praeger. However, both these perspectives have the language style of men as normative, implying that women's style is inferior.
More recently, Deborah Tannen has compared gender differences in language as more similar to 'cultural' differences ("cultural difference approach"). Comparing conversational goals, she argued that men have a report style, aiming to communicate factual information, whereas women have a rapport'' style, more concerned with building and maintaining relationships.
People tend to accommodate their language towards the style of the person they are interacting with. Thus, in a mixed-gender group, gender differences tend to be less pronounced. A similarly important observation is that this accommodation is usually towards the language style, not the gender of the person . That is, a polite and empathic male will tend to be accommodated to on the basis of their being polite and empathic, rather than their being male.