AbstractThis article investigates the manner in which students in Norwegian upper secondary schools negotiate “legitimate speaker” category membership in spoken interactions. It is concerned with adolescents’ linguistic identity as Norwegian speakers, and the language ideologies that inform categorization practices. Three collaborative features are distinguished to identify membership categorization practices: the pragmatic notion of scales of time and place; pronouns, in particular the personal pronouns “we”, “us”, and “they”; and the socio-epistemic notion of object-side assessments. The article asks whether the students’ categories correspond to those of education policy and research, and finds that students operate with more complex membership categorizations than the binary Norwegian/non-Norwegian division found in applied linguistic research and policy documents. It also finds that status as “expert” speaker of Norwegian is negotiable in student interactions, where social factors such as interpersonal relations, perceived social differences and performance of category-bound activities are as important as linguistic factors. The article shows how both non-native and native speakers of Norwegian can discursively construct themselves and others as more or less expert speakers of the language. As such, it contributes with insights on how institutionally defined linguistic markets, linguistic capital and legitimate speakers can be contested at the local level of student interactions.