怎样判断判断主语从句和强调句.都是it is...that...

问题描述:

怎样判断判断主语从句和强调句.都是it is...that...

主语从句that不充当任何成分
强调句that充当一定成分

It is(或was)…that …句型中若去掉it is (或was)和that不影响句意,则此句式为强调句;
若去掉it is(或was)和that后句意不完整,则此句为主语从句.
It was about 600 years ago thatthe first clock with a face and an hour hand was made.(强调句)
It is possible that he has stolen the car.(主语从句)