1. It’s + 形容词/名词 + (for sb.) + to do
Eg. It is easy for me to find a friend.
2. It’s + 形容词 (important/ essential/ necessary) + that sb. (should) do
Eg. It is important that students (should) study hard.
3. It’s + 名词 (pity/ shame) + that sb. should do
Eg. It is a pity that he did not pass the exam.
4. It’s (high/ about) + time hat sb. should do/ did
Eg. It’s (high/ about) time hat workers should have a rest/ had a rest.
5. It/ This is +the + 序数词 + time that sb. have/ has done
It/ This was +the + 序数词 + time that sb. had done
Eg. It/ This is the second time that Kathy has gone to Beijing.
6. It is/ was not until...that
Eg. It was not until his wife came back that he went to bed.(强调句)
7. It (suddenly) occurred to sb. that...
Eg. It suddenly occurred to Tom that he did not finish the homework.
8. It is no use/ no good doing sth.
Eg. It is no use/ no good staying up.
9. There is no doubt that...
Eg. There is no doubt that doing exercise is beneficial to our health.
10. The reason (why...) is that...
Eg. The reason (why Tom did not finish his homework) is that he forgot this issue