1
强调句:It is/was + 强调部分 + that/who +……
判断方法:把It is/was 和that/who省去掉,剩下的词语能构成一个完整的句子,如:
It was his ability that enabled him to have many friends.是他的能力使他能够拥有许多朋友。
His ability enabled him to have many friends. 他的能力使他能够拥有许多朋友。
2
主语从句 +
谓语动词 + ……
= It + 谓语动词 + …… + 主语从句
it是
形式主语,意思和位置上都代替了真正主语(主语从句)。
It is a good idea that we go climbing.
That we go climbing is a good idea.
这里面的it is 和that都不能省略掉,省略之后,就不是一个完整正确的句子。本回答被提问者采纳