This article uses a sociolinguistic approach to understand the "other tongues" of Acts 2. Existing interpretations of the phrase other tongues are shown to be problematic. The linguistic concept of diglossia is proposed and applied to the Acts 2 narrative. Diglossia refers to a situation in which a multilingual community uses different languages, each with a distinct set of social functions. Where a diglossia is connected with religion, there is a differentiation between the liturgical/sacred language and the ordinary/profane language. The Acts 2 narrative appears to describe the violation of the customary first-century Judean diglossia. Hebrew was the sacred language, and Aramaic and Greek were the everyday languages. The phrase other tongues refers to the lower languages spoken by the disciples and means simply "other than Hebrew."