Language geography is the branch of human geography that studies the geographic distribution of language or its constituent elements. There are two principal fields of study within the geography of language: the "geography of languages", which deals with the distribution through history and space of languages, and "linguistic geography", which deals with regional linguistic variations within languages. Various other terms and subdisciplines have been suggested, including: a division within the examination of linguistic geography separating the studies of change over time and space; 'geolinguistics', a study within the geography of language concerned with 'the analysis of the distribution patterns and spatial structures of languages in contact', but none gained much currency.
Many studies have researched the effect of 'language contact', as the languages or dialects of peoples have interacted. This territorial expansion of language groups has usually resulted in the overlaying of languages upon existing speech areas, rather than the replacement of one language by another. An example could be sought in the Norman Conquest of England: Old French became the language of the aristocracy but Middle English remained the language of the majority of the population.
Linguistic geography, as a field, is dominated by linguists rather than geographers. Charles W. J. Withers describes the difference as resulting from a focus on "elements of language, and only then with their geographical or social variation, as opposed to investigation of the processes making for change in the extent of language areas." Peter Trudgill says, "linguistic geography has been geographical only in the sense that it has been concerned with the spatial distribution of linguistic phenomena." Greater emphasis has been laid upon explanation rather than mere description of the patterns of linguistic change. That move has paralleled similar concerns in geography and language studies. Some studies have paid attention to the social use of language and to variations in dialect within languages in regard to social class or occupation. Regarding such variations, lexicographer Robert Burchfield notes that their nature "is a matter of perpetual discussion and disagreement" and notes that "most professional linguistic scholars regard it as axiomatic that all varieties of English have a sufficiently large vocabulary for the expression of all the distinctions that are important in the society using it." He contrasts this with the view of the historian John Vincent, who regards such a view as
"a nasty little orthodoxy among the educational and linguistic establishment. However badly you need standard English, you will have the merits of non-standard English waved at you. The more extravagantly your disadvantages will be lauded as 'entirely adequate for the needs of their speakers', to cite the author of Sociolinguistics. It may sound like a radical cry to support pidgin, patois, or dialect, but translated into social terms, it looks more like a ploy to keep Them (whoever Them may be) out of the middle-class suburbs."— John Vincent, The Times
Burchfield concludes, "Resolution of such opposite views is not possible.... future of dialect studies and the study of class-marked distinctions are likely to be of considerable interest to everyone."
In England, linguistic geography has traditionally focussed upon rural English,rather than urban English. A common production of linguistic investigators of dialects is the shaded and dotted map showing to show where one linguistic feature ends and another begins or overlaps. Various compilations of these maps for England have been issued over the years, including Joseph Wright's English Dialect Dictionary (1896–1905), the Survey of English Dialects (1962-8), and The Linguistic Atlas of England (1978).
In 1965, Prof. Mario A. Pei of Columbia University founded the American Society of Geolinguistics (ASG), which holds meetings during the academic year at Baruch College of the City University of New York. Under the editorship of Wayne H. Finke (ASG secretary) and Leonard R. N. Ashley (ASG president), the ASG publishes the annual journal Geolinguistics and holds an annual international conference not only on language geography but all aspects of language in contact in the modern world with attention to language acquisition, language teaching, change and impact upon culture and commerce, politics, economics, social dynamics in general. Geolinguistics goes beyond linguistics to connect to anthropology, ethnology, history, political science, studies of cognition and communication, etc. ASG's international conference draws participants from the US, Europe, Asia, Australia, etc., and the keynote speakers have been among the leaders in the field of linguistics in connection with modern society.
- Delgado de Carvalho, C.M. (1962). The geography of languages. In Wagner, P.L.; Mikesell, M.W. Readings in cultural geography. Chicago: University of Chicago Press, 75-93.
- Dell'Aquila, V. (1997). Mapping the languages of Europe in Herberts K., Laurén C., Laurén U, Strömann S. (Eds.): "Flerspråkighetens dimensioner. Individ, familj och samhälle", Vaasan Yliopiston Julkaisuja: Vaasa/Vasa, 103-131.
- Pei, M. (1966). Glossary of linguistic terminology. New York: John Wiley.
- Trudgill, P. (1974). Linguistic change and diffusion: description and explanation in sociolinguistic dialect geography. Language in Society 3:2, 215-46.
- Trudgill, P. (1983). On dialect: social and geographical perspectives. Oxford: Basil Blackwell; New York: New York University Press.
- Trudgill, P. (1975). Linguistic geography and geographical linguistics. Progress in Geography 7, 227-52
- Withers, Charles W.J.  (1993). Johnson, R.J. The Dictionary of Human Geography, Gregory, Derek; Smith, David M., Second edition, Oxford: Blackwell, 252-3.
- Iordan, I.; Orr, J. (1970). An introduction to romance linguistics. Oxford: Basil Blackwell; Berkeley: University of California Press.
- Williams, C.H. (1980). Language contact and language change in Wales, 1901-1971: a study in historical geolinguistics. Welsh History Review 10, 207-238.
- Weinrich, U. (1974). Languages in contact. The Hague: Mouton.
- Burchfield, Robert  (2003). The English Language, New York: Oxford University Press, 14.
- Withers, C.W.J. (1984). Gaelic in Scotland 1698-1981: the geographical history of a language. Edinburgh: John Donald; Atlantic Highlands, NJ: Humanities Press.
- Giglioli, P.P. (1972). Language and social context. Harmondsworth: Penguin.
- The Times, 23 February 1983, p. 12
- Burchfield, Robert  (2003). The English Language, New York: Oxford University Press, 128-130.
- In 1985, one could still say, "We still know far more about the distribution of byre/shippon/mistall/cow-stable/cow-house/cow-shed/neat-house/beast-house for 'cow-shed' than we do about urban synonyms for pedestrian crossings, lollipop men, machines used to wash cars, forecourts of petrol stations, bollards, sleeping policemen, pay-out desks, supermarket trolleys, traffic wardens, telephone booths and hundreds of other items found in every city in the United Kingdom." Burchfield, Robert  (2003). The English Language, New York: Oxford University Press, 128.
- Burchfield, Robert  (2003). The English Language, New York: Oxford University Press, 125.