He wants to know the reason why,为何用why,reason是状

He wants to know the reason why,为何用why,reason是状 I don't know the reason why he did't come to the meeting yes I don't know the reason why he was absent yesterday.reason后面 not know the reason why的意思 The reason why he didn't go to school was that he was ill.为什 I don’t know the reason why he said these words.里面的why引导的从句是 The reason why\that 关于The reason why the reason(why\which) he explained The reason why 可以代换为the reason for which 是the reason for还是the.reason.why the reason that和the reason why