第3讲 代词（要点透析）
it的用法
一、 指示代词
1. 指代上文提过的事物。
That vase is valuable. It's more than 200 years old.
那个花瓶很珍贵，它有200多年的历史。
【辨析】one, ones, it, that, those
it特指上文提到的某人和某物；相当于the＋名词。
one 指上文提到的某人或某物中任何一个。复数形式是ones。one前面若有形容词修饰，必须用冠词。
We've got a big room and two small ones.
我们有一间大房间和两间小房间。
I have a storybook. It is an amusing one.
我有一本故事书，它是有趣的。
that和those常有后置定语修饰，有特指意义，that代替不可数名词或单数可数名词，相当于the＋名词；复数名词用those，相当于the ones。
The weight of an elephant is much greater than that of a horse.
大象比马重得多。
【知识运用】
①- I can't find my watch.
- You haven't found ______？ If you want to buy a new ______， I suggest you buy ______ made in China.
②The books on the first shelf are easier than ____________ on the second shelf.
③The boy told him his story and also __________ of the girl upstairs.
【答案】①it; one; one ②those/the ones ③that/the one
2. 指代人时，常指小孩或身份不明的人。
- Someone is knocking at the door. Who is it?
- It must be Leo. He said he'd come to see me.
3. 指代环境或情况。
It's too quiet in the room. Everyone just keeps silent.
4. 指代时间、季节、天气或距离。
It is spring now and it's warm these days.
【疑难点击】
it指代时间时，有如下句型：
(1) It is timefor sth.
(for sb.)to do sth.
that－从句( should do/ did，必须用虚
拟语气)
It's time for lunch.
It's time for us to clean the house.
It's time that we should clean the house.
＝It's time that we cleaned the house.
(2) It is /has been ＋ some time ＋ since－从句(从句用一般过去时)(注意从句中延续性动词意义为否定。)
It is three years since I became a doctor.
我当医生已经3年了。(自从我成为医生以来，时间已经过去3年了。)
It is three years since he was a doctor.
他不当医生已经3年了。
It is two years since my father smoked.
我父亲不吸烟已有两年了。
It is two years since my father began to smoke.
我父亲吸烟已有两年了。
(3) It/This is the first /second…time that－从句(必须使用现在完成时) 这是某人第……次做了某事。
It/That was the first/ second…time that－从句(必须使用过去完成时)
It is the second time that she has visited the Great Wall.
This was the first time that I had come late to school.
(4) It was ＋时间点 ＋ when－从句
It was evening when we got home.
＝It was evening in which we got home.
(5) It was / will be ＋ some time ＋ before－从句
It was five years before they finally graduated from Beijing University.
过了5年他们终于从北大毕业。
It won't be long before we graduate from our school.
不久，我们就要从我们学校毕业了。
二、it 作形式主语，代替由不定式、动名词或名词性从句所表示的真正主语或宾语。
It is possible for me to make a tour around the world.
It is no good learning English without speaking it.
Mobile phones make it possible for us to keep in touch anywhere.
I consider it no good chatting with strangers through the Internet.
I really find it a pity that you didn't come to the party.
三、强调句型
1. 强调句结构：It is / was ＋ 被强调部分 ＋ that ＋ 句子的其余部分。
说明：(1)it是引导词，强调的内容可以是句子的主语、宾语、状语。如果被强调的部分是人，that 可用who代替，其他情况一律用that。
It was Edison who invented the lamp.
(2)验证强调句的方法： 去掉It is/was…that 结构后，可以把被强调的部分与句子其余部分还原为一个完整的句子。
2．注意时态的一致性。原句中用的是过去的某种时态， 用it was…that…； 原句中用的是现在或将来的某种时态，用it is…that…
3. 当被强调的部分是主语时，注意保持主谓一致。
It is I that am your English teacher.
4. not …until…结构用于强调句中，not 要提前到until之前，放在be动词后。即：It wasn't until…that ＋句子的其余部分。
He didn't go to bed until he finished his homework. (对画线部分进行强调)
→ It wasn't until he finished his homework that he went to bed. (强调句)
5．强调句中的被强调部分含有一个定语从句，要注意区别、分析。
It is/was ＋被强调部分＋定语从句＋that(who)＋句子的其余部分
It is in the city where he was born that he works.
他工作的地方是他出生的那个城市。
四、带it 的一些固定词组
1．(You've/I've)got it. 懂了，明白了。
- Do remember to take this medicine three times a day with warm boiled water.
- Got it.
2. forget it 算了吧，别在意，没关系
- I really appreciate your timely help.
- Forget it. It's just a small cake.
3. take it easy 别着急，慢慢来；别过于紧张
There's nothing serious with your stomach. Take it easy.
4. It comes to nothing. 没有什么结果。
They had a heated discussion, but it came to nothing.
5. Don't mention it. 不用谢。
6. That's it. 对了；正是。
- Is it your watch that you are looking for?
- Yes, that's it.
7. When it comes to…当谈到……； 当涉及……
When it comes to the matter, she just kept silent.
this, that, these, those的用法
指示代词this，that，these，those 在句中相当于名词和形容词，可作主语、表语、定语和宾语。
1. this/these 常指后面要提到的事物，有启下的作用；that/those 指前面讲过的事物，有承上的作用。
John was hurt in an accident，and that is still a secret to his father.
All I want to say is this：He must go to see a doctor.
2. 为了避免重复，可用that或those来代替前面提到的名词。
The climate of Beijing is not so damp as that of Qingdao. (that＝the climate)
The regulations in our school are quite different from those of yours. (those＝the regulations)
3. this，these是时间或空间上的“近指”，可与here 连用；that，those 是时间或空间上的“远指”，可与there连用。
Those were the days when we were happy together.
因此打电话时，用this来介绍自己，用that来问对方，不用I或you.
This is Wang Tao speaking.Who is that?
规则3: society表示“我们居住的社会”时， space表示“星球间的距离即太空”时， nature表示“大自然”时， most表示“大多数”， man 表示“人类”，word表示“消息”时都不用冠词。
Racism exists at all levels of society.
种族主义存在于社会各阶层。
4. those 可代替those persons 在句中用作关系代词的先行词，后跟定语从句。
Those who break the rules and regulations will be punished.
5. this，that 在口语中有时作状语用，相当于副词so，表示程度，意为“这么”、“那么”。
The food is this fat, and I don't want that much.
no, none, nothing, no one, nobody的用法
5个词都表示全部否定。
no＝not any，表示“没有”，用来修饰可数名词或不可数名词，通常作定语。
none 即可指人也可指物，常回答how many, how much 引导的问句；代替不可数名词作主语时，谓语动词用单数形式；代替可数名词作主语时，谓语动词可用单数也可用复数形式。
no one 只能指代人，常回答who引导的问句，后不可接of 短语。
nothing 只能指物，常回答what 引导的问句。
- What can you see in the hole?
- Nothing.
- Who are in the room?
- No one/Nobody.
- How many boats are there in the river?
- None.
【注意】none 强调数的概念，nothing表示“什么也没有，没有东西”。
Nothing can prevent me from studying hard.
He had many friends, but none would help him when he is in trouble.
both, all, either, neither的用法
1. both与all 用作定语、宾语、主语和同位语，all还能作表语。both表示“两者都”，all表示“所有的、全部的”，指三个或三个以上的人或物。
Both of the boys are here. (主语)
They all have been to Xi'an. (同位语)none 强调数的概念，nothing表示“什么也没有，没有东西”。
Nothing can prevent me from studying hard.
He had many friends, but none would help him when he is in trouble.
2. either 指“两者都不”；neither 指“两者中都不”，在句中作主语、宾语和定语。
either, neither 可与or, nor 构成连词：e