A native English speaker, Castonguay was sent by his parents to a French Catholic primary school. He took his first English courses in high school. Enrolled in the Canadian Armed Forces to pursue university-level studies, he obtained a masters of mathematics from the University of Ottawa. During the three years of his military service, he was posted to National Defence headquarters in Ottawa as counsellor in mathematics and also taught young officers at the Collège militaire royal de Saint-Jean.[1]
After his service, he began teaching mathematics and statistics at the University of Ottawa and registered at McGill University to study the philosophy of mathematics and epistemology. The subject of his doctoral thesis was "meaning" and "existence" in mathematics. He obtained his Ph.D. in 1971.[1] The thesis was published in 1972 and 1973.
"The Fading Canadian Duality", in Language in Canada (ed. John R. Edwards), pp. 36–60, Cambridge: Cambridge University Press, 1998, 520 pages
"Assimilation Trends among Official-Language Minorities. 1971-1991", in Towards the Twenty-First Century: Emerging Socio-Demographic Trends and Policy Issues in Canada, pp. 201–205, Federation of Canadian Demographers, Ottawa, 1996
"The Anglicization of Canada, 1971-1981", in Language Problems and Language Planning, vol. 11, issue 1, Spring 1987
"Intermarriage and Language Shift in Canada, 1971 and 1976", in Canadian Journal of Sociology, Vol. 7, No. 3 (Summer, 1982), pp. 263–277
"The Economic Context of Bilingualism and Language Transfer in the Montreal Metropolitan Area", in The Canadian Journal of Economics, Vol. 12, No. 3 (Aug., 1979), pp. 468–479 (with Calvin J. Veltman, Jac-Andre Boulet)
"Why Hide the Facts? The Federalist Approach to the Language Crisis in Canada", in Canadian Public Policy, 1979
"Opportunities for the Study of Language Transfer in the 1971 Census", in Paul Lamy (ed.), Language Maintenance and Language Shift in Canada: New Dimensions in the Use of Census Language Data, Ottawa: Ottawa University Press, 1977, p. 63-73.
"An Analysis of the Canadian Bilingual Districts Policy", in American Review of Canadian Studies, 1976
Richard Marcoux, Book Review of Charles Castonguay, Les indicateurs généraux de vitalité des langues au Québec : comparabilité et tendances 1971-2001, in Recherches sociographiques, XLVII-2, May–August 2006 : 394-397.
