This research attempts to clarify the difference between Japanese learners’ intended tonicity and performed tonicity, i.e., between their knowledge and practice. The results were as follows: (1) The subjects tended to put a nucleus on the stressed syllable of the last word in each intonation phrase. They typically used high level pitch to highlight the word that they thought they had to put a nucleus on. (2) Their intended tonicity was strikingly better than their performed tonicity. (3) There was greater discrepancy between intended tonicity and performed tonicity when they had to find correct tonicity on their own than when they were provided with it. (4) We need to consider two kinds of errors: (a) error in intended tonicity (error in knowledge) and (b) error in performed tonicity (error in putting knowledge into practice). (5) Teaching tonicity requires providing with knowledge plus exercise to put knowledge into practice.