This study examined native English speakers' reactions to nonnative primary stress in English discourse. I measured North American undergraduate students' processing, comprehension, and evaluations of three versions of an international teaching assistant's speech: with primary stress correctly placed, incorrectly placed, or missing entirely. Results indicated that when listening to speech with correct primary stress, the participants recalled significantly more content and evaluated the speaker significantly more favorably than when primary stress was aberrant or missing. Listeners also tended to process discourse more easily when primary stress was correct, but the result was not significant. These findings provide insights into how using primary stress affects international TAs' intelligibility. They also provide empirical support and suggest new ideas for current pedagogical practices that emphasize suprasegmentals in teaching pronunciation. (Contains 5 tables.)