分析句子成分what's the most important,she is warm-heartedwhat's the most important,she is warm-hearted一句中,what's the most important是什么成分?这其中有什么句型吗?what怎么翻译?

主系表结构的特殊疑问句。
what抽象意义“什么”,作表语 ，也可理解为主语。

what is the most important插入语，she is warm-hearted主句。what东西/事物（或者不翻）——what is the most important最重要的（东西/事情）是，她是热心肠的

what's the most important,she is warm-hearted一句中,what's the most important是什么成分?这其中有什么句型吗?what怎么翻译?
What's the most important is that she is warm-hearted
引导主语从句,what=the thing that 因此可以改写为的带有定语从句和表语从句的复合句
The thing that is the most important is that she is warm-hearted
主语：The thing
修饰主语定语从句：that is the most important
系动词：is
表语：that she is warm-hearted
或者说是这样
主语：What's the most important (主语从句作主语）
系动词：is
表语：that she is warm-hearted （表语从句作表语）
一上复合句,简称为“主表从句