Perception experiments suggest that natives judge non-native unfilled pauses as indiscriminate and indecisive. Multiple regression analyses of unfilled pauses indicate a connection between syntactic structure and pause location and duration. Native speakers uniformly pause at large syntactic breaks with marked duration, whereas non-nativesÂ’ unfilled pauses are spread over various locations, possibly reflecting limited syntactic planning. Our method might be used to synthesize appropriate unfilled pauses in text-to-speech systems, and to train pausing behavior in automated pronunciation learning systems for nonnative learners.