【简介】感谢网友“雕龙文库”参与投稿，这里小编给大家分享一些，方便大家学习。
一、强调句
（一）强调句句型
1、陈述句的强调句型：It is/ was + 被强调部分（通常是主语、宾语或状语）+ that/ who（当强调主语且主语指人）+ 其它部分。
e.g. It was yesterday that he met Li Ping.
2、一般疑问句的强调句型：同上，只是把is/ was提到it前面。
e.g. Was it yesterday that he met Li Ping?
3、特殊疑问句的强调句型：被强调部分（通常是疑问代词或疑问副词）+ is/ was + it + that/ who + 其它部分？
e.g. When and where was it that you were born?
4、强调句例句：针对I met Li Ming at the railway station yesterday.句子进行强调。
强调主语：It was I that (who) met Li Ming at the railway station yesterday.
强调宾语：It was Li Ming that I met at the railway station yesterday.
强调地点状语：It was at the railway station that I met Li Ming yesterday.
强调时间状语：It was yesterday that I met Li Ming at the railway station.
5、注意：构成强调句的it本身没有词义；强调句中的连接词一般只用that, who，即使在强调时间状语和地点状语时也如此，that, who不可省略；强调句中的时态只用两种，一般现在时和一般过去时。原句谓语动词是一般过去时、过去完成时和过去进行时，用It was ，其余的时态用It is 。
（二）not until 句型的强调句
1、句型为：It is/ was not until + 被强调部分 + that + 其它部分
e.g. 普通句：He didnt go to bed until/ till his wife came back.
强调句：It was not until his wife came back that he went to bed.
2、注意：此句型只用until，不用till。但如果不是强调句型，till, until可通用；因为句型中It is/ was not 已经是否定句了，that后面的从句要用肯定句，切勿再用否定句了。
（三）谓语动词的强调
1、It is/ was that 结构不能强调谓语，如果需要强调谓语时，用助动词do/ does或did。
e.g. Do sit down. 务必请坐。
He did write to you last week. 上周他确实给你写了信。
Do be careful when you cross the street. 过马路时，务必（千万）要小心啊！
2、注意：此种强调只用do/ does和did ，没有别的形式；过去时用did ，后面的谓语动词用原形。
二、It的用法
（一）作人称代词
1、it代替前面（或后面）的单数名词或分句等所表示的事物。
e.g. You cannot eat your cake but have it.（it代替前面的cake）
Although we cannot see it, there is air all around us. （it代替后面的air）
They say he has left town, but I dont believe it. （it代替前面Theytown分句中的情况）
2、代替有生命但不能或不必分阴阳性的东西（包括婴儿）。
e.g. Yesterday we saw a big tree. It was fully twenty metres high. （it代替前面的tree）
The baby cried because it was hungry. （it代替前面的baby）
3、在某些习惯说法中，可以代替人。
e.g. ---- Someone is knocking at the door, Peter. ---- Who is it? ---- Its me.
---- Who are singing? ---- It is the children.
---- The light is still on in the lab. It must be the third-year students doing the experiment.
4、it与one的区别：这两个词都可以代表前面说过的名词，但it用于同名同物的场合；one则用于同名异物的场合。
e.g. ---- Do you still have the bicycle? ---- No, I have sold it.
---- Is this knife yours? ---- No. It is Xiao Zhangs. Mine is the one on the desk.
5、it与that的区别：两词都可代替某一特定名词，但that指同一类，并非同一个。
e.g. The climate of South China is mild（温和的）; I like it very much.（it指the climate of South China）
The climate of South China is much better than that of Japan.（that指the climate）
（二）作无人称代词
it作无人称代词时，除了句中找不到它所代表的词语外，另一个特点是它后面的内容都是表示天气、时间、距离、度量衡及情况等。
It is fine (rainy, windy, etc.).
It is noon.
It is a half hours walk to the factory.
It is eighteen square metres in area.
What does it matter?
（三）作强调词，构成强调结构
用以帮助改变句子结构，使句子的某一成分受到强调。It is (was) + 所强调的成分 + that (who) + 其它成分。在这个句型中，it本身没有词义。详见一、强调句。
（四）引导词it作形式主语（宾语）
为了使句子平衡，常采用形式主语（或宾语）it ，而把真正的主语（或宾语）置于句子后面。通常引导词it与它所代替的句子成分中间要夹有某些词。
e.g. It takes half an hour to go there on foot.（It与to go there on foot之间夹有takes half an hour四个词）
We thought it strange that Mr Smith did not come last night. （it与that从句中间夹有 strange）
但有时it与所替代部分之间并不夹有其它词。
e.g. You may depend on it that they will support you.（因为介词on之后一般不直接接that引导的宾语从句。注意：it不是多余的，不能当作错句）
练习一、强调句、It的用法
1. My bike is missing. I cant find ____ anywhere.
A. one B. ones C. it D. that
2. ---- Whos that? ---- ____ Professor Li.
A. Thats B. Its C. Hes D. Thiss
3. ____ was Jane that I saw in the library this morning.
A. It B. He C. She D. That
4. ---- Have you ever seen a whale alive? ---- Yes, Ive seen ____.
A. that B. it C. such D. one
5. The color of my coat is different from ____ of yours.
A. this B. that C. it D. one
6. ____ will do you good to do some exercise every morning.
A. It B. There C. Those D. You
7. We think ____ our duty to pay taxes to our government.
A. that B. this C. its D. it
8. The climate of Shanghai is better than ____ of Nanjing.
A. that B. it C. which D. what
9. ____ four years since I joined the Army.
A. There was B. There is C. It was D. It is
10. How long ____ to finish the work?
A. youll take B. youll take it C. will it take you D. will take you
11. It was through Xiao Li ____ I got to know Xiao Wang.
A. who B. whom C. how D. that
12. It was in the rice fields ____ we had our league meeting.
A. where B. that C. in which D. on which
13. It was on October 1st ____ new China was founded.
A. which B. when C. as D. that
14. Was it because he was ill ____ he asked for leave?
A. and B. that C. thats D. so
15. Mary speaks in a low voice; ____ is difficult to know what she is saying.
A. it B. that C. so D. she
16. It was ____ I met Mr Green in Shanghai.
A. many years that B. many years before C. many years ago that D. many years when
17. ____ is not everybody ____ can draw so well.
A. It, all B. It, that C. There, who D. There, that
18. So ____ that no fish can live in it.
A. shallow is the lake B. the lake is shallow C. shallow the lake is D. is the lake shallow
三、省略
为了使讲话和行文简洁，句中某些成分有时可省略。省略可分以下几种情况：
（一）简单句中的省略
1、省略主语：祈使句中主语通常省略。其它省略主语多限于少数现成的说法。
e.g. (I) Thank you for your help.（括号内为省略的词语，下同）
(I) see you tomorrow. (It) Doesnt matter.
2、省略主谓语或主谓语的一部分。
e.g. (There is) No smoking. (Is there) Anything wrong? Why (do you) not say hello to him?
3、省略作宾语的不定式短语，只保留to。
e.g. ---- Are you going there? ---- Id like to (go there).
He did not give me the chance, though he had promised to (give me the chance).
注意：如果该宾语是be动词或完成时态，则须在to之后加上be或have。
e.g. ---- Are you an engineer? ---- No, but I want to be.
---- He hasnt finished the task yet. ---- Well, he ought to have.
4、省略表语。
e.g. ---- Are you thirsty? ---- Yes, I am (thirsty).
5、同时省略几个成分。
e.g. Lets meet at the same place as (we met) yesterday.
---- Have you finished your work? ---- (I have) Not (finished my work) yet.
（二）并列句中的省略
两个并列分句中，后一个分句常省略与前一分句中相同的部分。
e.g. My father is a doctor and my mother (is) a nurse.
I study at college and my sister (studies) at high school.
（三）主从复合句中的省略
1、主句中有一些成分被省略。
e.g. (Im) Sorry to hear that you are ill.
(It is a) Pity that he missed such a good chance.
2、省略了一个从句或从句的一部分，用so或not（切不可用it或that）代替。
e.g. ---- Is he coming back tonight? ---- I think so.
---- Is he feeling better today? ---- Im afraid not.
这种用法常见的有：How so? Why so? Is that so? I hope so. He said so 及I suppose not. I believed not. I hope not等。（但I dont think so比I think not更常用）。
（四）其它省略
1、连词that的省略：
①、宾语从句中常省略连词that，但也有不能省略的情况（参看名词性从句等有关部分）。
②、在定语从句中，that在从句中作宾语时可省略。
③、引导主语从句、同位语从句等的连词that一般不可省略。在表语从句中偶尔可省略。
2、不定式符号to的省略
①、并列的不定式可省去后面的to。
e.g. I told him to sit down and wait for a moment.
②、某些使役动词（如let, make, have）及感官动词（如see, watch, notice, hear, feel, look at和listen to等）后面作宾语补足的不定式一定要省去to，但在被动语态中须把to复原。
e.g. ---- I saw the boy fall from the tree. ---- The boy was seen to fall from the tree.
③、介词but前若有动词do，后面的不定式不带to。
e.g. The boy did nothing but play.
3、在某些状语从句中，从句的主语与主句主语一致时，可省去主语 + be部分。（参看状语从句有关部分）
4、连词if在部分虚拟条件句中可省略，但后面的语序有变化（参见倒装句有关部分）
5、主句与从句各有一些成分省略。
e.g. The sooner (you do it), the better (it will be).
四、插入语
英语句子中（尤其在口语中）常插入一些单词、短语或者句子，用来补充某些含义。语法上称他们为插入语。
（一）插入语的类型：
1、单词（多是副词），如：besides, however, otherwise, therefore, though等。
e.g. She is looking fit, though. 他看起来倒是健康。
I can, however, discuss this when I see you.
2、短语
e.g. China and India, for example, are neighbours.
By the way, where are you from?
3、句子
e.g. He is an honest man, I believe.
Jack, as far as I know, isnt clever.
（二）插入语的位置
通常插入语位于句中，并用逗号隔开。但有时，也可位于句首或句末（见上面例句）。也有时，并不用逗号隔开。
e.g. You know that I think you are wrong. 我认为，你明白你错了。
What on earth do you mean? 你究竟是什么意思？
（三）插入语在句中的作用
一般来说，插入语在句中不起主要作用。如果把插入语抽去，句子的含义不大受影响。但是，有的插入语却是句子不可缺少的一部分。
e.g. He got the news from nobody knows where. 他这消息谁也不知道是从哪儿得来的。
（四）插入语的特殊用法
下面这种复杂的特殊疑问句，也可认为包含有插入语。这种疑问句（有的语法书也称为混合疑问句或连锁疑问句）常用来征询对方对某一疑问点的看法、判断、认识、猜度或请求对方重复一遍说过的话。口语中出现频率极高。常用动词有say, suppose, guess, believe, consider, think, imagine 等。
e.g. How long did you say she would stay here?
When do you suppose theyll be back?
How old did you think she was
（五）大纲中要求掌握的常用作插入语的词语
by the way 顺便说，顺便问一下；so far 到目前为止；and so on 等等；on the contrary 相反； no wonder 不足为奇；as a matter of fact 事实上；come along 快点，来吧；in other words 换句话说；as usual 如同以往；as a result 因此，结果。
练习二、省略和插入语
1. ---- Wont you have another try? ---- ____.
A. Yes, I will B. Yes, I wont C. Yes, I will have D. Yes, I wont have
2. ---- I wont do it any more. ---- ____?
A. Why dont B. Why dont do it any more C. Why not D. Why not do
3. ---- Do you think it will snow tomorrow? ---- ____.
A. No, I dont think B. I dont think C. No, I dont so D. I dont think so
4. ---- Will he fail in the exam? ---- ____.
A. Dont hope to B. Lets hope not C. Not hope so D. Lets hope not to
5. ____ usual, I have forgotten something.
A. As B. As it is C. Its D. That is
6. ____ she a man, she might be elected president.
A. If B. Unless C. Was D. Were
7. ____ I had time, I would have played it again.
A. If B. Unless C. Had D. When
8. ____ it rain tomorrow, Id stay at home.
A. Should B. Would C. When D. If
9. I like sports and ____ my brother.
A. so B. so does C. so is D. so likes
10. Francis, ____ born in Kentucky, lived and practised law in Missouri.
A. was B. He was C. who is D. although
11. ---- Arent you the manager? ---- No, and I ____.
