Language contact is one of the many phenomena sociolinguistics pays attention to, and whose pioneer work may be considered to be Weinreich 1953. This work has paved the way for a number of sociolinguists interested in the evolution of languages in a situation of multilingualism and who have highlighted the importance of a series of conditions in the survival of the languages in contact (cf., among many others, Milroy 1980, Appel & Muysken 1987, Romaine 1989, Milroy and Milroy 1992, De Bot & Stoessel 2002, Mufwene 2001, 2008). Among the many factors that condition language contact situations, we isolate those of prestige, volatility and social network structure and build a model of language competition, in the line of Abrams & Strogatz 2003 and Minett & Wang 2008. Our model brings about qualitative results such as the role of bilingualism as an accelerator of language death (comparable to the case of Quechua in Peru, for example), the role of volatility in the emergence of new linguistic varieties (comparable to the case of Spanglish in the US), and the importance of social network structure in the resilience of threatened languages (comparable to the Sea Island Creole in the US). Abrams, D.M., Strogatz, S.H., 2003. Nature 424, 900. Appel, René & Pieter Muysken. 1987. Language Contact and Bilingualism. Amsterdam: Amsterdam University Press. De Bot, Kees, & Saskia Stoessel. 2002. International journal of the sociology of language, 153: 1-7. Milroy, Lesley and James Milroy. 1992. Language in Society 21: 1-26. Milroy, Lesley. 1980. Language and social networks. Oxford: Blackwell Minett, James W. & William S-Y. Wang. 2008. Lingua 118: 19-45. Mufwene, Salikoko. 2001. The Ecology of Language Evolution. Cambridge: C.U.P. Mufwene, Salikoko. 2008. Language Evolution. Contact, Competition and Change. London/New York: Continuum International Publishing Group. Romaine, Suzanne. 1989. Bilingualism. Oxford: Blackwell. Weinreich, Uriel. 1953. Languages in contact. Findings and Problems. Hague: Mouton.