It is 句型 1
It is + 被强调部分 + that
该句型是强调句型
将被强调的部分放在前面,其它部分置于that 之后
被强调部分可以是主语,宾语,表语或状语
强调的主语如果是人,that 可以由who 换用
如果把这种句型结构划掉后,应该是一个完整无缺的句子
这也是判断强调句型与其它从句的方法
It was about 600 years ago that the first clock with a face and an hour hand was made
It was they that (who ) cleaned the classroom yesterday
It was in the street that I met her father
It is not until + 被强调部分 + that
该句型也是强调句型
主要用于强凋时间状语,译成汉语"直到...才...",可以说是 not
It was not until she took off her dark glasses that I realized she was a famous film star
= Not until she took off her dark glasses did I realize she was a famous film star
= I didn’t realize she was a famous film star until she took off her dark glasses
It is clear ( obvious, true, possible, certain
) that
该句型中it 是形式主语,真正的主语是th