1.it is 形容词 that从句 同样是做主语这个that从句能改成what名词从句吗?2 动词+it+宾补+后置定语 ①后置定语为to do 或是that从句（除定语从句,同位语外）要保留形式宾语it.②后置定语为what从句

Question

1.it is 形容词 that从句 同样是做主语这个that从句能改成what名词从句吗?
2 动词+it+宾补+后置定语 ①后置定语为to do 或是that从句（除定语从句,同位语外）要保留形式宾语it.②后置定语为what从句或名词词组,it要去掉.
请问这样概括对不对?
this calls into question all of our cultural assumptions that gay men are feminine.
请问1和2有什么联系?
终于搞明白了 非常谢谢！
“真正宾语”的doing 能帮我举个例子以便理解吗？
“真正宾语”为what从句或名词词组，是it要去掉。（参照英语语法新思维-高级篇 P167页）

书上的例子为 many people consider impossible what really is possible.

Answer 1

1.不能.因为that是连词,而what是代词
It is important that we learn English.
2.后置定语应该是“真正宾语”；（1）真正宾语为：to do; that从句；还有doing,当然得保留形式宾语了.（2）真正宾语为what从句时（比较少见）,it也不能去掉.名词词组是真正宾语,或者你说的“后置定语”,应该没有这种结构.
I think it important that we learn English.
I think it important to learn English.
1与2的共同点就是都有it充当形式主语/宾语