I don’t know the reason why he said these words.里面的why引导的从句是

I don’t know the reason why he said these words.里面的why引导的从句是 定语从句的引导词当先行词是reason的时候,引导词一定用why吗?例:I don`t believe the reas 想找一首歌的歌名 里面有一句歌词是"i don't want be the reason why" the reason why.这里why引导的是什么从句啊 I don't know the reason why he was absent yesterday.reason后面 The reason why he did it was not clear.这句话why引导的是什么从句 I don't know the reason why he did't come to the meeting yes The teacher know why he came late.why引导的是定语从句还是宾语从句,如果是前者,先行 I don't know __.A.the reason why can be B.why the reason may 定语从句do you know the reason why he didn't come?为什么可以用why?从句后h 定语从句do you know the reason why he didn't come? Do you know the reason why/for which he didn't come?这句话的意思?