Mari Jones specialises in French linguistics, especially language death theory and dialectology.
Major publications include Variation and Change in Mainland and Insular Norman (Brill, 2015); The Guernsey Norman French Translations of Thomas Martin: A Linguistic Study of an Unpublished Archive (Peeters, 2008); Exploring Language Change (Routledge, 2005); Jersey Norman French: A Linguistic Study of an Obsolescent Dialect (Blackwell, 2001); Language Obsolescence and Revitalization (Oxford University Press, 1998) and La langue bretonne aujourd'hui à Plougastel-Daoulas (Brud Nevez, 1998). She is also editor of Policy and Planning for Endangered Languages (Cambridge University Press, 2015); Endangered Languages and New Technologies (Cambridge University Press, 2014); Keeping Languages Alive (Cambridge University Press, 2013); Language and Social Structure in Urban France (Legenda, 2013); Les Langues Normandes: Pluralité, Normes, Représentations (L'Harmattan, 2009); The French Language and Questions of Identity (Legenda, 2007) and Language Change: The Interplay of Internal, External and Extra-linguistic Factors (Mouton de Gruyter, 2002).
She is interested in all aspects of language change, dialectology, language contact and questions of standardisation. Her research has focused particularly on Welsh, Breton and - at present - Insular and Mainland Norman.
Current research projects include directing an international research network funded by the AHRC on language and social structure in urban France and major collaborations with the University of Caen: "Patrimoine Linguistique en Normandie" and with the University of Rennes, where she is a research associate at L'Equipe de Recherche sur la diversité Littéraire et Linguistique du monde Francophone:. She is also Visiting Professor in Linguistics at the University of Bamberg, Visiting Fellow at the University of Canterbury, Christchurch, New Zealand and Fellow of the International Centre for Language Revitalisation.
Her graduate teaching focuses on Language death theory, Language variation and Sociolinguistics, both within the context of French and of other languages.
She is founder of the Cambridge Endangered Languages and Cultures Group and the Cambridge Conferences in Language Endangerment series.
She is a Fellow of the Learned Society of Wales.