why在定语从句中做原因状语时，不能换成that请看下面我给你分析的两个句子,想必看完之后，你就会对why引导的原因状语从句的应用有一个彻底的掌握的句①He wanted to know the reason.句②I was late for the reason.把句②变为句①的定语从句，句①中的the reasons做定语从句的先行词。因为the reason做介词for的宾语，先行词是the reason指物，在定语从句中介词for提前，用关系代词which替代the reason，the reason就不能在定语从句中出现了。由此得到句③He wanted to know the reason for which...
有reason(原因)这个词，用that 和 why均可， 没有这个词，得用why the reason why （或者that）he left her 他离开她的原因 * That is (the reason) why I came early. 这就是我来早了的原因. that is why i came early,这个就不行...
