对啊.如果不用形式主语,举个例子 (That we wait for him right now )is impossible.我们现在不可能等他的. 这个句子很明显,that 从句是主语从句. 即使把句子改成用it作形式主语 It is impossible that we wait for him right now. that引导的那个句子仍然是主语从句.
我同意二楼的意见 it is wonderful that you will become the lead singer of our rock and roll band. 你将成为我们摇滚乐队的主场真是太好了。 it=that引导的从句,it 是形式主语,真正的主语是that引导的句子,因此得出: it做形式主语时,that引导真正主语,that从句属于主语从...