Gökçe: Bilingualism/multilingualism need not be a transitional situation in cases of language contact. It is a stable linguistic situation in many (most?) places around the world.
There may be language loss without multilingualism being involved, as for example in cases of monolingual aphasia. Language assimilation, in turn, usually means an affirmation of mainstream monolingual practice, in places where monolingualism is the official take on language policies, and where there is therefore little or no support/regard for multilingualism.
Ethnicity has little to do, again, with official language policies and official recognition of actual language use.
So I’m not entirely clear on why bilingualism/multilingualism should be understood as a stage leading to instances of monolingualism. Perhaps you will want to give us one or two examples of situations which led you to formulate this research question in this way?
Madalena: Many thanks for the answer. Surely there are many places on earth where bilingualism / multilingualism is a stable situation. Additionally there are examples of situations which language does not directly entail assimilation. For instance many minority groups in Peoples Republic in China have lost their language but still are recorded as minority groups. Manchurians could be listed among others. However, today in southeastern Turkey the Karakechili Turkomans around the city of Urfa has become almost monolingual in Kurdish and have kurdified. Likewise in the past many Turkish villages in Cyprus has lost Turkish completely and become grecified after conversion to Christianity. Examples like these make me wonder weather bilingualism does entail assimilation sooner or later.
According to Cook's idea of multi-competence, anybody can have differing degrees of competence in different languages. So, acquiring a second language does not necessarily influence the first language leading to such conditions as language loss or assilmilation.
The Canadian case is certainly very interesting and informative on this issue, and there are also interesting similarities with the situation in Catalonia, Spain. There is a chapter that you might be interested in checking: “Les services d’accueil, d’intégration scolaire et de francisation offerts aux immigrants au Québec”, by zita De Koninck. Chapter 11 in: Rodríguez-García, D. (ed.) (2012) Managing Immigration and Diversity in Canada: A Transatlantic Dialogue in the New Age of Migration, Montreal and Kingston: McGill-Queen’s University Press.
There is a summary in English of this chapter and a comparison with the Spanish case in the Introduction of the book, which is available on my ResearchGate site: https://www.researchgate.net/publication/260248380_Managing_Immigration_and_Diversity_in_the_New_Age_of_Migration_A_Transatlantic_Dialogue
Cheers,
Dan
Chapter Managing Immigration and Diversity in the New Age of Migrati...