The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social groups, the sociology of work needs to develop a better understanding of the way in which linguistic diversity influences the formation of social capital (i.e. resources such as the trust and reciprocity inherent in social relations in such workplaces). Drawing on theories about intergroup contact and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, while communication related to collaboration and ‘small talk’ may provide linguistic bridges to social capital formation.