本研究著重兩個方向：（一）比較非母語人士與母語人士之ToBI架構有何不同：ToBI架構分別根據由八位已經學習七年美國英文之臺灣學生和八位美國英語之母語人士所讀之英文句子所標註；（二）找出臺灣學生學習英語語調困難的因素。本研究資料顯示三個不同點：斷音型態不同 (break、index)、重音落點不同、及語調線斜率 (Bost-fit 1ine) 之不同。就斷音型態而言，英語母語人士斷音有固定模式，臺灣學生則沒有固定的斷音模式，且與母語人士很不相同。就重音落點而言，英語母語人士重音都落在相同之音節，而臺灣學生則沒有固定的重音節。同時，英語母語人士之音調線斜率明顯大於臺灣學生之音調線斜率。希望本研究之發現對英語音調教學有某種程度的助益。

This study focuses on two things: (1) to try to contrast the ToBI labels based on the oral data produced by eight native speakers of American English and eight Mandarin-speaking college students who have studied American English for at least seven years in Taiwan; and (2) to locate salient features that interpret why it is difficult for EFL students in Taiwan to acquire intonation of American English. Data show that great discrepancies fall on three major features: the pattern of the break index (BI), the location of the pitch accent in each intonation phrase (IP), and the slope of the best-fit line of each IP. While American English speakers consistently break their utterances at a certain boundary so that they produce similar IPs for most utterances, Mandarin speakers break without definite patterns. In addition, while native speakers of American English consistently place the pitch accent on a certain stressed syllable, Mandarin speakers place their pitch accents on a great variety of locations. Finally, the slopes of the best-fit trendlines of the IPs in American English speakers' utterances are consistently steeper than those in Mandarin speakers' IPs. The findings are expected to provide useful information concerning the suprasegmental features in English. The introduction of the ToBI system might also be helpful for EFL students in Taiwan in acquiring the subtle prosodic features of American English.