“I can see the reason that he is so positive is because he believes in himself.”一句的句子成分？

“I can see the reason that he is so positive is because he believes in himself.”一句的句子成分？

这是多重复合句。

〔主句〕I can see （我可以看得出）
〔宾语从句〕the reason ... is because he believes in himself （其原因是因为他相信自己）
〔嵌套同位语从句〕that he is so positive （也就是他如此积极的原因）追问不对啊，the reason后面的表语从句用that不用because。还有，that he is so positive如果是同位语从句，那表语从句也一样的是解释the reason的内容，两者都解释同一个内容，而且解释还不一样。追答同位语从句是具体说明属于什么含义的 reason，because 引导的表语从句是表明 导致 the reason 的具体原因，二者意思并不重复。