in the United States since independence in 1776, hundreds of aboriginal languages were spoken before western European settlement. French was once the main language in Louisiana, Missouri, and areas along the border with Quebec, but the speaking has dwindled after new waves of migration and the rise of English as a lingua franca. Californio Spanish became a minority language during the California Gold Rush; it has largely been overtaken by English and Mexican Spanish, surviving mainly as a prestige dialect in Northern and Central California. German was once the main language in large areas of the Great Plains and Pennsylvania, but it was suppressed by anti-German sentiment during the First World War. Vietnam Since the fall of Saigon at the end of the Vietnam War in 1975, French has declined heavily in Vietnam from being a government language and primary language of education in South Vietnam to being a minority language limited to the elite classes and elderly population. Today, French is spoken fluently by less than 1% of the Vietnamese population. The language shift from French to Vietnamese occurred earlier in the north due to Viet Minh and later communist policies enforcing Vietnamese as the language of politics and education. However, since the late 1990s, there has been a minor revival of French in Vietnam. Reversing American linguist Joshua Fishman has proposed a method of reversing language shift which involves assessing the degree to which a particular language is disrupted in order to determine the most appropriate method of revitalising. See also Endangered language Extinct language Germanic substrate hypothesis Koiné language Language death Linguistic imperialism Second language World Englishes Notes References Sources Bastardas-Boada, Albert (2007), "Linguistic sustainability for a multilingual humanity", Glossa. An Interdisciplinary Journal (on-line), vol. 2, n. 2. Bastardas-Boada, Albert (2002), "Biological and linguistic diversity: Transdisciplinary explorations for a socioecology of languages", Diverscité langues, vol. VII, Analyses et réflexions (on-line) Further reading Bastardas-Boada, Albert. From language shift to language revitalization and sustainability. A complexity approach to linguistic ecology. Barcelona: Edicions de la Universitat de Barcelona, 2019. External links Language Shift in Australia and Canada SIL Bibliography: Language shift - Ethnologue.com The Rate of Assimilation : Francophone Minorities: Assimilation and Community Vitality - Department of Canadian Heritage shift Sociolinguistics Shift Shift Cultural assimilation Articles containing video clips