一、the reason why肯定是
定语从句二、the reason that 不一定都是定语从句,分以下两种情况
1.当that后面加的句子是完整的句子的话,那它肯定是
同位语从句,例如
He gave me the reason that he got up too late this morning.
2.当that 后面加的句子是不完整的句子的话(也就是缺少主语、宾语或
表语时),那它就是定语从句了,例如
I believe the reason that he gave.
He gave me the reason that was unbelievable.(他给了我一个令人难以置信的解释