句型1：it+be+adj.(for sb./of sb.)to do
it is difficult(for me)to learn russian.(我)学俄语是件困难的事。
it is very kind of you to help me.你帮助我真是太好了。
句型2：it +be +adj.+that
it is true that he went there.他去了那儿，是真的。
句型3：it +be +time +for +n.
it +be +time(for sb.)+to do
it's time for class.该上课了。
it's time(for us)to go to school.(我们)该上学了。
句型4：it+be+时间/季节/天气/距离
it's seven now.现在七点了。
it's winter now.现在是冬季。
it's sunny today.今天阳光灿烂。
it's twenty miles to london.这里离伦敦有20英里。
句型5：it's one's turn(to do)
it's your turn to speak.轮到你发言了。
句型6：it +takes/took+sb.+some time +to do
it took me two hours to finish the work.我用了两小时完成这项工作。
句型7：it seems that...
it seems that he has been ill for a long time.他好像病了很长时间。
句型8：it +costs +sb.+some money +to do
it cost me 1，000 yuan to buy that bike.买那辆自行车我用了1000元。
句型9：it +be +some time +since...
it is three years since he came here.他自来这儿以来，已经三年了。
句型10：it +be +quite +a(an)+adj.+n.
it's quite a nice book.它是一本相当好的书。