國際音標應用於英語發音教學，有優點，也有缺點。優點是可使學生立即擺脫英文望似雜亂無章的拼字系統的困擾。缺點是，因而造成一代學生，由於長期依賴國際音標，而完全忽視英文本身原來也有些道理的拼字系統，不懂什麼是長母音，什麼是短母音。英文學到一定程度，進行書面作業，或編輯排版，所必需的音節劃分原理，就正是配合這個區分長短母音的拼寫法而形成的。比如很多人不明白為什麼profit的正確劃分法是prof-it, 而program的正確劃分法是pro-gram。本文有鑒於此，特將英文所謂的長短母音，與國際音標(DJ&KK)列了一個照對表，並依據Webster’s國際英文大字典之導言說明，編寫了若干條音節劃分規則，並詳細舉例示之，藉供各級英文教師、教授及從事英文專業人士參考。

In the application of the IPA symbols to the teaching of English pronunciation, there are both advantages and disadvantages. The greatest advantage lies in clearing up all the seeming irregularities in the English traditional spelling system by referring the pronunciation of a word directly to the IPA symbols. However, the advantage also brings on its disadvantage because, due to long-time practice of the IPA symbols for pronunciation, to the complete disregard of the traditional not entirely unreasonable spelling system, students turn out to be entirely ignorant of the distinction between the so-called ‘long’ and ‘short’ vowels which is regularly observed in the English traditional spelling system. And the most important syllabication rules rightly rest upon such ‘long’ - ‘short’ vowel distinctions. To salvage the situation, this article aims to sort out a number of practical rules, along with plenty of illustrations, to help English teachers and page editors to do a better job in syllabication in their professional performance.