请教各位that、what 和 which 在集中名词性从句中分别充当什么成分？麻烦举例子详细说明，谢谢各位

名词性从句的引导词分三种：连接词 包括that ,whether ,if
连接代词 包括what，which , who , whom, whose, whatever等
连接副词 包括 when, where, why, how
连接词在从句中不做成分，that引导从句，不做成分，没有意义 ， whether和if也不做成分，意义为是否
连接代词在从句中一般做主语或宾语，也有定语和表语，并且有意义。what可做主语，宾语，表语和定语，which可做主语，宾语和定语
连接副词在从句中做状语，也有意义
如： That he came to school late made the teacher angry.
Can you tell me what you are looking for? what做从句的for的宾语
She is no longer what she used to be. what做从句be 的表语
I don't know what side effect the medicine will bring about. what做从句side effect的定语
I want to know which is right. which做从句的主语
Tell me which book you like best. which做从句的定语

希望可以帮到你啊！

what \that \which 充当主语和宾语,不同的是，what 没有先行词，其他2个都要有的。

如：
I don't know what to do?

We know that the earth goesaround the sun.(宾语从句)

关系代词which 指物,如果作从句的宾语,则有时省略。如：Have you foundthe book which you lost several days ago?(你找到几天前丢失的那本书了吗？)

关系代词that既可指人也可指物,如果作从句的宾语,则有时省略。如：Can you see theman/dogthat is running along the river bank?(你看得见顺着河跑的男人/狗了吗？)

希望对你有用。