Language revival often retains founding overt beliefs rooted in an ideological commitment to a specific language because of its role as the authentic, legitimate cultural vehicle of a distinct people. Revival is thus the reinstatement of cultural distinctiveness based on traditional language. Revivalists have afforded traditional language varieties prestige status based on perceived ethnolinguistic authenticity. However, after a century of language revivalism, some minoritised languages have regained some of their vitality through ‘new speakers’ who have no direct relationship with the traditional language. The ways that new speakers and ‘learners’ of displaced languages negotiate linguistic authenticity and ethno-cultural legitimacy in late modernity provide challenges to established perceptions about language revitalisation and regeneration of traditional speech communities and the belief in the prestige of ‘native’ speech as the target variety. This discussion draws on interviews with speakers of Irish and Manx Gaelic to analyse both their overt and more hidden beliefs about the utility and legitimacy of traditional and revival speech. It will argue that ‘traditional’ and ‘new’ speakers do not live parallel sociolinguistic realities in which they are sociolinguistically isolated from one another, but that contemporary speakers contest the prestige of both traditional and innovative varieties in a multifaceted fashion.