We discuss the duration of the breath group between pauses as an English speech unit observed in our developed speech corpus of movies. We used both an automatic pause-detecting system and a manual processing using linguistic information to collect 19,551 breath groups in total. We then analyzed the length of the breath groups in distribution. The result shows that the average duration is 1.9 seconds and 87% of them are within 3.0 seconds, which is considered to be similar to the reported cognitive time constraints for language processing such as the working memory and its supposed phonological loop. Based on the result of our observations into the duration of the breath groups, we suggest teaching methodologies and CALL materials which should enable the novice learners to process English speech and shadow-read the text on a chunk-by-chunk basis, which is within 3 seconds and preferably around 2 seconds in time.