Most english vowel sounds which are not given weight in speech become reduced to a rather formless central vowel 在言语中不重读的英语元音大部分被弱化成无形的中元音。
Sentence stress isn ' t " fixed " like word stress . in fact , you can stress words that are normally unstressed in order to highlight different meanings 句中重读并不像单词重音那样固定不变。事实上,你可以通过在平时不重读的词上重读来突出不同意义。