1 It is adj for sb to do,sth

2 It is/has been 时间段 since 一般过去时.

译:自从…已经多长时间了

3 It's (high/about) time that​早该…了/早该…时候了，从句中要求:主语 should 动词的原形，should不可省略

4 It's /was​ 被强调的部分 that/who 其他成分，典型的强调句结构

5 It's 表示建议，命令，要求，坚持的词 that从句，从句要求:主语 (should) 动词原型，should一般可以省略哦

6 It is the first/second/third time that (that可以省略，it可以换成this/that等,句式里如果前面是is，后面从句用have done,如果前面是was，从句中要换成had done)

7 It is no good /use doing sth：做…没有好处/没用

8 It's said/reported /announced/believed that…that后才是真正主语

这里是一个主语从句，it做的还是形式主语.

9 It's a pity/shame that…主语 should v原形，should可以省略

10 It looks/seems as if /though似乎/好像…

11 It doesn't matter whether/if不论/是否…

12 It occurs to/comes to/strikes/hits sb that

译:某人突然想起…/突然发生…

13 When it comes to (doing)当谈到…什么，这里面需要注意的是to是介词，后面通常接doing sth

你还想到哪些特殊句式呢，欢迎在下方留言补充，如果觉得有用别忘啦点赞收藏啊，谢谢~