句型1.
It (so) happened（chanced） that +clause. = sb. happened /chanced to do sth. =sb.did sth.by chance. 如：
It happened that he was out when I got there. 当我到那儿时，碰巧他不在。＝He happened to be out when I got there.= It chanced that he was out when I got there= He was out by chance when I got there.
句型2.
It seems that sb. do/ be doing/ have done/ had done= Sb. seems to do/ be doing/ have done/to be done/to have been done（还有动词appear等可这样使用）如:
It seemed that he had been to Beijing before.他好象以前去过北京。＝He seemed to have been to Beijing before.
句型3.
It is / was＋被强调的部分＋that(who)+剩余的部分.如：
It wasn't until he came back that I went to bed.直到他回来我才睡觉。(一定要注意被强调句型中的谓语动词否定的转移)。 It was because he was ill that he didn't come to school today.只因为他有病了今天没有来上学。（只能用because而不能用for, as 或since）
It is I who am a student. 我确实是个学生。（句中am不能用are来代替。）
句型4.
It is high time (time/ about time)+ (that) 主语＋should do / did+其它。（从句中的谓语动词用的是虚拟语气。）如:
It is high time that we should go / went home.我们该回家了。作者: martinyee123 时间: 2010-11-19 10:06
