This study looks at whether Taiwan Mandarin speakers were able to detect discourse boundary cues in Mandarin (Guoyu and Putonghua), English, and Japanese. Results showed that there was a distinct language effect. Mandarin boundaries were harder to detect than English and Japanese boundaries for these listeners. This is thought to be due to the different boundary cue compositions in the four languages, as the magnitude of Mandarin boundary cues was not as strong as that of English and Japanese (Fon, 2002). However, the perceptibility difference disappeared once listeners became more familiar with the stimuli. Motor preparedness and subjects’ expectation also played a role in determining RT.