⑴It’s +adj. +for/of +sb. to do sth.
It’s important for you to learn English well.
⑵It’s time for sb.to do sth.
It’s time for you to sing
⑶It seems that .....It seems that you are right.
⑷It’s one’s turn /job/duty to do sth.
It’s your turn/job/duty to clean the desk.
⑸It’s +adj. that 从句It’s necessary/certain/natural that he wiil win.
⑹It’s no use /good doing sth.做某事没有用处/好处。
It’s no use /good eating too much
⑺It’s +一段时间since +一般过去时态从句或It has been +some time +since +一般过去时态从句It’s(been) five years since we saw last .
⑻It’s a pity that ......It’s a pity that only six pieces of music in total were recorded for the future world to hear.
⑼It is said that/It is consider that/It is believed that ......It is said that he became a famous pianist.
动词(feel,think,make,believe,consider,suppose等)+it +adj./n.+ to do sth.
I think it necessary to learn English well.