In the context of classroom communication, there is a premium on the clarity of the message, and instructors will typically employ multiple linguistic cues to highlight information structure. Using a model of intonation in discourse [Brazil, D. (1986). "The communicative value of intonation in English." Birmingham, England: University of Birmingham, English Language Research. Brazil, D. (1997). "The communicative value of intonation in English." Cambridge: Cambridge University Press.], this paper examines the use of intonational paragraphs as an organizational tool in the teaching discourse of native speaker teaching assistants and nonnative speaker international teaching assistants at a North American university. Analysis of the native speaker data presents evidence of intonational paragraphs defined by phonological criteria and used by the speakers to underscore local and global information structure. Comparative analysis of the parallel nonnative speaker data shows a considerably weaker control of intonational structure and a disturbance in prosodic composition that materially affects the comprehensibility of the discourse for native speaker hearers. The paper closes with a discussion of some of the implications of this study for international teaching assistant programs.