今天小编为大家准备了职称英语备考：以形式主语it引导的句型，希望对大家有所帮助，接下来跟小编一起来看看吧。
　　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。
　　句型5.
　　It is /was said ( reported…) that 从句. 如：
　　It was said that he had read this novel.据说他读过这篇小说。=He was said to have read this novel.
　　句型6.
　　It is impossible /necessary/strange…that clause.(从句中的谓语用should do /should have done，其形式是虚拟语气。)如：
　　It is strange that he should have failed in this exam.真奇怪，他这次考试没有及格。
　　句型7.
　　It is a pity/a shame…that clause.(注意从句中的谓语动词用should do或should have done的形式，但should可以省略。)如：
　　He didn't come back until the film ended. It was a pity that he should have missed this film. 他直到电影结束才回来。他没有看到这部电影真可惜。
　　句型8.
　　It is suggested /ordered/commanded /…that clause.(从句的谓语动词用should do,但should可以省略。)如：
　　It is suggested that the meeting should be put off.有人建议推迟会议。
　　句型9.
　　It is/was 表示地点的名词 where 从句。(注意本句不是强调句型，而是以where引导的定语从句。)如：
　　It was this house where I was born.请比较：It was in this house that I was born.(后一句是强调句型。)
　　句型10.
　　It is /was 表示时间的名词 when 从句。(注意本句型也不是强调句型，而是以when引导的定语从句。)如：
　　It was 1999 when he came back from the United States. 请比较：It was in 1999 that he came back from the United States.
　　句型11.
　　It is well-known that 从句。如：
　　It is well-known that she is a learned woman.众所周知，她是个知识渊博的妇女。
　　句型12.
　　It is 段时间 since 主语 did. 请比较：
　　It was 段时间 since 主语 had done. 如：
　　It is five years since he left here.他已经离开这儿五年了。
　　It was five years since he left here.(同上)
　　注意下列句型的翻译:It is five years since he lived here.他从这儿搬走已经有五年了。
　　句型13.
　　It 谓语 段时间 before 主语 谓语.( before引导的是时间状语从句。) 如：
　　It wasn't long before the people in that country rose up.没有多久那个国家的人民就起义了。
　　It will be three hours before he comes back.三个小时之后他才能回来。
　　句型14.
　　It is 形容词(possible,impossible,necessary等) for sb. to do. 如：
　　It is impossible for me to finish this work before tomorrow.我明天之前完成此工作是不可能的。
　　句型15.
　　It is (心理品质方面的)形容词 of sb. to do.= 主语 be 形容词 to do.(常用的形容词有：kind,stupid;foolish,good,wise等。)如：
　　It is kind of you to help me.=You are kind to help me.你真好给我提供了帮助。