内容提要 1. it作人称代词,代替前面提到的事物. 2. it指代时间,季节,距离. 3. it作形式宾语,常用在6123结构中.(think , find, make, believe, …) 4. it作形式主语. 当动名词,不定式,从句作主语时,常用it作形式主语. 5. It is … that….的强调句型.
1．代替上文中提到过的人或事物。指代人时，一般用于小孩或身份不十分明朗的人。 例如： －Who is the baby? －It’s my teacher’s son． －Who is that gentleman? －It’s my friend, Tom．He (不可用It) wants to see you． 【典型例题】 (NMET2001) The Parkers bought a new house but _____ will need a lot of work before they can move in. A. they B. it C. one D. which B
2．用于表达天气、环境、时间、距离、季节等。2．用于表达天气、环境、时间、距离、季节等。 ◆ It’s half an hour’s walk from here to our school． ◆ It’s nice and warm here．But it’s two o’clock now, and it’s time for us to go to school． 注意下列几种表示时间的句型
①.It is time ( about time ,high time ) that ... ◆ It’s high time that we left. ②.It is the first ( second ... ) time that ... ◆ It’s the first time that I have been praised. ③.It is .... since ... ◆ It’s three years since they got married. ④.It is / was ... when ... ◆ It was 1949 when the PRC was founded. ⑤.It is / was ... before ... ◆ It will be two years before we meet again.
3. We think it important to learn a foreign language.该句型中的it 作形式宾语。为了记忆方便我们可称该句型为“6123结构”。6指主句中常用的动词：think, believe, make, find, consider, feel；1指的是形式宾语 it； 2指的是宾补的两种形式：形容词或名 词；3指的是真正宾语的三种形式：不定式短 语, 动名词短语或 that 引导的宾语从句。
4. It is necessary ( for sb. ) to do sth.此句型中的真正主语是不定式短语，主句中的形容词通常是表示重要性，紧迫性，频繁程度，难易，安全等情况的形容词，常见的形容词有：① important, necessary, natural ② easy , safe , common , normal , hard , difficult , dangerous , unusual, rare , impossible , pleasant 在①中的形容词作表语可以用从句改写， 如：It is important for her to come to the party. = It is important that she (should ) come to the party
It作形式主语时的几个常见句型: ①. It is kind ( of sb. ) to do sth.该句型中的不定式如果须要逻辑主语，则 须要前置介词 of, 而句型中的形容词必须是 能表示逻辑主语特征的形容词，常见的有： bad , brave , careless, clever , cruel , foolish , good （好心的）, honest , horrible , kind , lazy , modest , naughty , nice（有教养的）, polite, rude , silly , stupid , wise , wrong 这个句型可以改写为：sb. is kind to do sth.
②. It takes sb. ... to do sth. “做…要花某人…” ◆ It took me ages to repair my computer. ③. It is no good (use ) doing sth.该句型中的真正主语是动名词短语，主句中的表语可以是 no good , no use , no value, no importance … ◆ It’s no use crying over the spilt milk. ④. It doesn’t matter whether ( if ) ...＂不论（是否）…没关系… ◆ It doesn’t matter whether he is for my plan or not.
⑤. It happens (seems, appears ) that... ◆ It happened that I had seen this problem in some book. ⑥. It is said (reported, learned....) that ... “据说”（据报道，据悉．．．） ◆It is said that he has gone to New York to attend a medical meeting. ⑦. It is a pity ( a shame ... ) that ... ◆ It is a pity that we have lost the match with a close score.
⑧. It is important ( necessary, right, strange, natural...) that ...记住that 后的从句应用虚拟语气（should + 动词原形），should 可以省去． ⑨. It is suggested ( ordered ... ) that ... that 后的从句要用虚拟语气（should + 动词原形），should 可以省．常译为＂据建议；有命令…）
⑩. It is up to sb. to do sth. 该句型为“该由某人做…”。该句型中 up 后的to是介词。 ◆ It is up to him to clean our classroom today. 今天应由他做教室清洁。 ◆ It is up to parents to teach their children manners. 该由父母教孩子礼貌。
5. It is + 被强调部分 + that ...将被强调的部分放在前面，其它部分置 于 that 之后．被强调部分可以是主语，宾 语，表语或状语．强调的主语如果是人， that 可以由 who 换用．如果把这种句型结构 划掉后，应该是一个完整无缺的句子．这也 是与其 它从句区别判断的方法． 注意: It is not until + 被强调部分+ that ...强凋“直到…才…”，需将 not 置于 until 之前
It was in the year of 2002they set up a branch company in China. （09年6月） A.as B.that C.what D.which Look at the clock! It’s time work. （06年12月） A.we started B.we’ll start C.we’re starting D.we have started Is quite difficult for Mary to pass the interview. （05年6月 ） A.What B.This C.That D.It It was two years ago his sister became a doctor. （10年6月 ） A.that B.where C.who D.what D C B
强调句型 (sentence pattern) 1.构成 (structure) 强调人 It is /was +强调部分+that (who/whom) +其他成分 只能是 单数 强调除谓语以外的句子成分
They will have a meetingin the halltomorrow. 强调主语 It is they that/who will have a meeting in the hall tomorrow. 强调宾语 It is a meeting that they will have in the hall tomorrow. 强调地点状语 It is in the hall that they will have a meeting tomorrow. 强调时间状语 It is tomorrow that they will have a meeting in the hall.
It is your father who is wrong this time. It is his parents who havecome to China. 一致 主语 谓语 ①主谓一致：被强调部分作主语时，其形式与谓语动词在人称和数上保持一致。
It is Mary who often ____ (help/helps) me with my English. It is I that ____ (be) against you. It is the boy students of Class Two who ____ playing football on the playground. helps am are
It is Iwho am wrong. It was her whom I saw in the street just now. 主格 主语 宾语 宾格 ②人称照应：强调主语用主格，强调宾语用宾格。
这次得冠军的是她。 It was ____ that won the championship this time. 你明天要去采访的是他。 she It is himwho you will interview tomorrow.
③be前面可加情态动词 It must be Peter who has let this secret out. It may be next week that she leaves for Tokyo. It might be last night that the thief broke in their house.
④问句形式： 一般问句：Is/Was it + 被强调部分 + that + ---- Is it the dictionarythatyou are looking for? Was ityesterdaythathe was fired?
特殊问句：疑问词+is/was +it +that +----- Whatis it that you want me to do ? Whowas it that told you the news? When was it that you called me? How was it that you succeed?
他想申请的是这家公司吗？ ________________ that he wants to apply for? 你们是在哪里买到这本小说的？ Is it this company Where was it that you bought the novel?
⑤ 当强调not…until结构时，必须将 not until连用,后面接肯定式。 I didn’t realize what trouble he was in until at that time. It was not until at that time that I realized what trouble he was in.
The teacher didn’tstop his lesson until the bell rang. (改成强调句） It was not until the bell rang that the teacher stopped his lesson. 直到他父亲来了男孩才开始做作业。 It was not until his father came that the boy began to do his homework.
把“It is/was --- that”去掉，如果剩余部分句子结构仍然完整，那么这个句子就是强调句；如果句子不完整，则不是强调句。如： It is true that he once went to America. It was at 8 o’clock that he came back. 3. 强调句型的判断 主语从句 强调句型