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. 當(dāng)我到那兒時(shí)，碰巧他不在。＝He happened to be out when Igot there.= It chanced that he was out when I gotthere= 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（還有動(dòng)詞appear等可這樣使用）如:
It seemed that he had been to Beijing before.他好象以前去過(guò)北京。＝He seemed tohave been to Beijing before.
句型3.
It is / was＋被強(qiáng)調(diào)的部分＋that(who)+剩余的部分.如：
It wasn't until he came back that I went to bed.直到他回來(lái)我才睡覺(jué)。(一定要注意被強(qiáng)調(diào)句型中的謂語(yǔ)動(dòng)詞否定的轉(zhuǎn)移)。 It was because he was ill that he didn't come toschool today.只因?yàn)樗胁×私裉鞗](méi)有來(lái)上學(xué)。（只能用because而不能用for, as或since）
It is I who am a student. 我確實(shí)是個(gè)學(xué)生。（句中am不能用are來(lái)代替。）
句型4.
It is high time (time/ about time)+ (that) 主語(yǔ)＋should do / did+其它。（從句中的謂語(yǔ)動(dòng)詞用的是虛擬語(yǔ)氣。）如:
It is high time that we should go / went home.我們?cè)摶丶伊恕?/p>
句型5.
It is / was said ( reported…)＋that+從句. 如：
It was said that he had read this novel.據(jù)說(shuō)他讀過(guò)這篇小說(shuō)。＝He was said to have read this novel.
句型6.
It is impossible / necessary/ strange…that clause.(從句中的謂語(yǔ)用should＋do /should have done，其形式是虛擬語(yǔ)氣。)如：
It is strange that he should have failed in this exam.真奇怪，他這次考試沒(méi)有及格。
句型7.
It is + a pity/ a shame…that clause.(注意從句中的謂語(yǔ)動(dòng)詞用should do或shouldhave 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 missedthis film. 他直到電影結(jié)束才回來(lái)。他沒(méi)有看到這部電影真可惜。
句型8.
It is suggested / ordered/ commanded /…that +clause.(從句的謂語(yǔ)動(dòng)詞用should do, 但should可以省略。)如：
It is suggested that the meeting should be put off.有人建議推遲會(huì)議。
句型9.
It is/was＋表示地點(diǎn)的名詞＋where+從句。（注意本句不是強(qiáng)調(diào)句型，而是以where引導(dǎo)的定語(yǔ)從句。）如：
It was this house where I was born.請(qǐng)比較：It was inthis house that I was born.(后一句是強(qiáng)調(diào)句型。)
句型10.
It is / was +表示時(shí)間的名詞＋when+從句。（注意本句型也不是強(qiáng)調(diào)句型，而是以when引導(dǎo)的定語(yǔ)從句。）如：
It was 1999 when he came back from the United States. 請(qǐng)比較：It was in 1999 thathe cameback from the UnitedStates.
句型11.
It is well-known that＋從句。如：
It is well-known that she is a learned woman.眾所周知，她是個(gè)知識(shí)淵博的婦女。
句型12.
It is +段時(shí)間＋since+主語(yǔ)＋did. 請(qǐng)比較：
It was +段時(shí)間＋since+主語(yǔ)＋had done. 如：
It is five years since he left here.他已經(jīng)離開(kāi)這兒五年了。
It was five years since he left here.（同上）
注意下列句型的翻譯:It is five years since he lived here.他從這兒搬走已經(jīng)有五年了。
句型13.
It +謂語(yǔ)＋段時(shí)間＋before+主語(yǔ)＋謂語(yǔ).（ before引導(dǎo)的是時(shí)間狀語(yǔ)從句。） 如：
It wasn't long before the people in that country roseup.沒(méi)有多久那個(gè)國(guó)家的人民就起義了。
It will be three hours before he comes back.三個(gè)小時(shí)之后他才能回來(lái)。
句型14.
It is +形容詞(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。
