This article questions the sense of belonging throughout linguistic practices. The French language is historically perceived as a decisive marker of national belonging; as to the use of vernacular languages, they would reflect the vindication of regional affiliation. The analysis of interviews, carried out in Alsace and Bretagne in 2005, undermines this idea: territorial ties are not necessarily associated to the use of a language other than French, even if the fact of speaking Alsatian, Gallo or Breton may reinforce local roots and can be used as well to exclude those who are not able to speak it.