人教版九年级英语第十三单元基础知识
人教版九年级英语第十三单元知识点总结
Unit13.We’re trying to save the manatees!
一．单词
litter bottom fisherman coal ugly advantage cost wooden plastic takeaway bin shark fin cruel harmful be harmful to at the top of chain the food chain ecosystem industry law scientific take part in afford turn off reusable pay for take action transportation recycle napkin throw away put sth to good use pull...down upside gate bottle president inspiration iron work metal bring back creativity
二．1.现在进行时
定义：表示说话时（瞬间）正在进行的动作，也表示目前或现阶段一直进行的动作。
结构: ① 肯定句: 主语+ am/is/are + V-ing
① 否定句: 主语+ am/is/are + not + V-ing
① 疑问句: Am/Is/Are + 主语+ V-ing
用法：1）表示说话时正在进行的，目前正在发生的动作。
① Look! The big bird is flying away. ① He is watching a movie now.
2）表示目前一段时间内正在进行，但说话时可能没有进行的动作。
Right now I am studying Chinese by distance learning. 我现在正通过远程教育学习汉语。1) 2)常带有表示目前时刻的时间副词, 如：now, right now, at the (very) moment, for the time being, at present, these days 及Look! Listen! ...
3）与always, constantly, forever, all the time等副词连用，表示动作反复或习惯。此时句子常含有说话者的强烈情感在内。表达较强的“责备”或“表扬”之意
① You are always changing your mind. 你总是主意不定。(太烦人了)
① He is always helping others.他总是帮助别人。(他真是个好人)
4）对于come, go, leave, arrive, start,fly,drive等表示位置移动的动词常可用进行时态表将
来。
① He is leaving on Wednesday. ① Mary isn’t here at the moment. She is coming later.
2. used to do见第四单元及use用法
3.被动语态见第五单元
注意：接双宾语的词的被动语态；make /let /have sb do的被动语态；see/ hear /notice /find /observe sb do 的被动语态；It’s said/reported/believed/supposed/well-known；及无被动语态的三种情况（感官动词、不及物动词、sell/write等）
4.现在完成时:
用法：①过去发生的动作对现在造成的影响或结果：强调结果:
Yesterday I finished my homework, that’s to say, I have finished my homework now.
①过去已经开始一直持续到现在的动作或状态：强调继续
I have lived here since 1990.
现在完成时的构成have/has+过去分词
现在完成时的四个基本句型
肯定句He has finished the work. 一般疑问句Has he finished the work?
否定句He has not finished the work. 两回答Yes ,he has. No, he hasn’t.
特殊疑问句What has he done?
在下列情形下用现在完成时
1九词语
①already 已经肯定句中或句尾I have already found my pen. = I have found my pen already.
①yet已经否定句和疑问句句尾I have not finished the work yet.
Have you bought a computer yet?
①ever曾经句中Have you ever seen pandas?
①never从不句中I have never been to Beijing.
①just刚刚句中I have just done my work.
①before以前句尾I have never been there before.
①so far到目前为止So far he has learned 200 words.
①how long多久How long have you lived here?
①how many times多少次How many times has he been to Beijing?
2两词组
have
for two months for +一段时间Jim has lived here for 2
months.
since last year since +过去时
间点Lucy has been in Beijing since 3 years ago.
since 3 years ago since 1990
since he came here since +过去时
态句子He has been in China since he came here.
4如果句子里面没有时间状语，汉语意思能够加“已经”，往往用现在完成时态。Have you lost your library book? 你已经弄丢了从图书馆借的那本书吗？
5现在完成时态还常常用于下列句型
They have planted many trees in the last/past few years.
This is the best book I have ever read.
It is the first time I have played the computer games.
在现在完成时中，一次性动词不能和一段时间状语连用
例：He has bought the book for 3 years.（错）
因buy这个一次性动词不能和一段时间for 3 years连用, 改正的办法有：
He has bought the book.. (去掉一段时间for 3 years)
He bought the book 3 years ago (改为一般过去时，使句子的意思不变)
It’s/It has been 3 years since he bought the book. = 3 years has passed since he bought the book. （改为固定句型It is/It has been ---since---）
He has had the book for 3 years. （用延续性动词have代替buy）
另外
①come/arrive/get to/reach → be here
I have come here for 3 years.（错）改为：I have been here for 3 years.
①leave/go →be away
He has left for 3 hours.（错）改为：He has been away for 3 hours.
①begin/start →be on
The film has begun for 3 minutes.（错）改为：The film has been on for 3 minutes.
①open →be open / close → be closed
The shop has opened for 3 years.(错) 改为：The shop has been open for 3 years.
①die →be dead
His father has died for 3 years.(错) 改为：His father has been dead for 3 years.①finish/end→ be over
He has finished the work for 3 days.(错) 改为：The work has been over for 3 days ①join I have joined the army for 3 years.（错）
改为：I have been in the army for 3 years. 或I have been a soldier for 3 years.
①buy /catch → have
I have bought the bike for 3 years.（错）改为：I have had the bike for 3 years.
He has caught a cold for 3 days.（错）改为：He has had a cold for 3 days.
①borrow → keep
I have borrowed the book for 3 years. （错）改为：I have kept the book for 3 years.
还有其它的归纳如下：
break → be broken get up → be up marry → be married become → be lose → be lost
5. 情态动词
1) 情态动词本身有一定的词义，表示说话人的情绪、态度或语气，但不能单独作谓语，只能与其他动词构成谓语。常见的有：can (could), may (might), must, need, shall (should), will (would)等。
2) 情态动词无人称和数的变化, 后接动词原形。否定式是在情态动词后面加not。个别情态动词有过去式形式, 也可用来表达更加客气、委婉的语气。
1.can和could的用法
(1)can/could 表示“能力；许可；可能性”等。could 为can 的过去式。如：Can I use your bike?
(2)can 用在疑问句中，表示征求意见、请求许可，答语仍用can; could 用在疑问句中，比can 更委婉、客气，是一种礼貌的说法，并不表示过去时态，答语用can，而不能用could。如：—Could you tell me the way to the zoo?—Sorry. I can't. I'm new here。
[注意] can 和could 只能用于现在时和过去时两种时态，将来时中用be able to。另外，can't 可表示否定推测。如：That ______ be Mr Wang. He has gone to Beijing。
2.may和might的用法
may/might 意为“可以”，表示同意、许可或请求对方许可，也可表示祝愿。may的否定形式为may not。might 是may 的过去式，有两种用法：一种表示过去式；一种表示虚拟语气，使语气更加委婉、客气，或表示可能性更小。以may开头的一般疑问句，其否定
回答用mustn't, 而不用may not。如：______ I use your pen? 我可以用你用的钢笔吗？You may put on more clothes. May you be happy!
Might I borrow some money now?He might be alive.
3.must的用法
must 意为“必须，一定，准是”，表示说话人认为有必要做某事，或命令、要求别人做某事以及对事物的推测。否定形式mustn't, 表示“不得”，“一定不要”。如：
I ______ finish my work today。You mustn't drive after drinking。
(1)must 与have to 的区别：must 表示说话人的主观意愿；have to 表示客观需要。如：
I must do my homework first。It is raining hard outside; I _____ stay at home。
(2)回答由must 引导的疑问句的提问
①肯定回答：Yes, …must.如：
—Must I go home now? —Yes, you must.
①否定回答：No，…needn't./No，…don't/doesn't have to.
—Must I go home now? —No, you __ ____.
(3)must 表示对事物的推测，意为“想必；一定”，只用于肯定句中；表“推测”时，情态动词与动词原形，(常为be动词)连用，如：The man must be our teacher。
4.need的用法
(1)need 表示“需要，必须”，主要用于否定句和疑问句中。其否定形式为needn't，表示“没有必要，不必”；对由need构成的疑问句进行回答时，其肯定回答用must，否定回答用needn't。如
—Need we do some cleaning now?—Yes, you must. —No, you needn't.
(2)need 还可作实义动词，常用于下列结构：
①need to do sth“需要做某事”。如I need to learn more.
①need doing “某物需要被做”=need to be done。
如：My hair needs cutting. =My hair needs to be cut.
①need +名词或代词。如：All living things need water.
5.shall和should的用法
shall 用于第一人称的句子中，表示提建议或请求；should用于各种人称的句子中，强调义务或责任，意为“应该”。如：______ we go out for a walk?
You should study hard at school。
should have done主要有两个用法：
用于推测过去已经发生的情况。如：He should have arrived by now.
用于指本该发生而实际上未发生的情况。如：You should have told me so before.
6.will和would的用法
will用于第二人称疑问句时，表示征求意见或提建议；would 为will 的过去式，可用于多种人称，表示意愿。如：Will you have a little soup?
would have done主要有两个用法：
表“猜测过去”
I guess the poet would have been about twenty when she wrote her first poem.
表“过去本会发生，而实际并未发生”，没有责备之意。
I would have written before but I have been ill.本来我是会写信的，但是由于我生病了。（用来说明某一情况，没有责备之意）
7.have to
have to 的陈述句形式
肯定式：have to + 动词原形I have to tidy my room.我得整理房间.
否定式：don't (doesn't) + have to + 动词原形You don't have to go if you don't want to. have to 的一般疑问句形式及简略答语
have to的一般疑问形式必须借助助动词do 或does：