It's amazing how much this helped.句中为什么要用how much?how much this helped在句中是什么成分?

It's amazing how much this helped.句中为什么要用how much?how much this helped在句中是什么成分?
It's amazing how much this helped.句中为什么要用how much?how much this helped在句中是什么成分?

It's amazing how much this helped.句中为什么要用how much?how much this helped在句中是什么成分?
是主语从句,it在句中是形式主语,真正主语是how much this helped.
之所以要用how much而不是how many,是因为help的对象是个不确指的东西,这种情况下,往往要用指示不可数对象的how much,how many的对象必须明确是可数的东西.

主语从句

It’s amazing how much this helped．
真是不可思议了，这样做很有帮助。
It's amazing + 从句／to do sth “……真是太惊奇了”。
how much this helped 在这里是从句，可以从上面的句子结构中看出。