In lieu of an abstract, here is a brief excerpt:The discourse I focus on in this study comes from interviews and ethnographic work with Sri Lankan university youth. While diglossia theory proves insufficient in depicting the way these youth mix ‘formal’ and ‘colloquial’ morphosyntactic features in the same social setting, Agha’s register approach to Sinhala optimally accounts for the specific dialogic effects speakers attach to linguistic features, suggesting such interdiscursive meaning combined with sociohistorical backgrounds of the varieties explains the registers’ composite recognition as divergent.