1.那要分析句子的成分和句子的意思,我举个例子:He is a teacher.他是一个老师,句子的结构是:主语+系动词+表语,这时,be就是系动词,表示系表结构。2.助动词be的用法:1) be +现在分词,构成进行时态,例如:They are having a meeting. 他们正在开会。English is becoming more and more important. 英语现在越来越重要。2) be + 过去分词,构成被动语态,例如:The window was broken by Tom.. 窗户是汤姆打碎的。English is taught throughout the world. 世界各地都教英语。...