there is no reason why you should't tell them in advance what you are going to do.他

问题描述:

there is no reason why you should't tell them in advance what you are going to do.他
做什么句法成分

你没有理由不事先告诉他们你要做的事情.
why 为关系副词 ,引导定语从句,修饰reason 的 .
句型很简单 就是个there be 句型 ,然后主语被定语从句修饰,而定语从句里又有个what 引导的名词性从句 .
够清楚了么 不客气