初三英语第九单元

Unit 9 When was it invented?

二、重难点提示：

1．I think the telephone was invented before the car.

（1）invent v. 发明，制造

e.g. Bell invented the telephone. 贝尔发明了电话。

invention n. 发明，制造，发明物

e.g.This is one of Edison’s inventions.这是爱迪生的发明之一。

（2）was invented 意为“被发明”，是被动语态。

被动语态：The Passive Voice.

被动语态表示主语是动作的承受者。

其构成是：be动词＋及物动词的过去分词

一、概念：英语中及物动词有两种语态，即主动语态（The Active Voice）和被动语态（The Passive Voice）。主动语态表示主语是动作的执行者（谓语动作是主语来做的），被动语态表示主语是动作的承受者（谓语动作是由宾语来做的）。

二、构成：被动语态是由“be + done(动词的过去分词)”构成的。be动词由人称、时态和单复数的变化。

三、如何判断句子是主动语态还是被动语态？

看句子的谓语部分是否有be和done。

1．I have found my pen.（主动）

2．Jane was doing her homework.（主动）

3．The tree was planted by us. （被动）

四、如何将句子从主动语态变成被动语态？

Many people visit the Great Wall every year.

第一步：找出原句的谓语动词，将它变成be+过去分词形式。visit—be visited

第二步：找出原句的宾语the Great Wall，将它放在句首（如果是人称代词，要把它变成主格）变成被动句的主语，首字母大写。

第三步：根据被动句主语的单复数来确定be动词的形式。be—is

第四步：找出原句的主语many people，将它放在谓语动词之后或者句末（如果是人称代词，要把它变成宾格），首字母小写，并在前面加上介词by。

第五步：原句中其他部分（every year）直接抄写在被动句中，不作改动。

被动句是：The Great Wall is visited by many people every year.

B．主动语态变被动语态的方法：

把主动语态变为被动语态，要作以下变动：

（1）把主动结构的宾语变成被动结构的主语，把主动结构的主语变成被动结构中介词by的宾语。当不需要强调动作的执行者时，by短语可以省略。

e.g. I clean the bedroom every day.

→T he bedroom is cleaned by me every day.

He bought a new car yesterday.

→A new car was bought by him yesterday.

（2）主动结构的动词由主动变为被动时注意原句的时态和主语的单复数，以此来决定动词be的时态和单、复数。

e.g. I water the flowers every morning.

→The flowers are watered every morning.

e.g. Mr. Green repaired the bike himsel

f.

→The bike was repaired by Mr. Green himself.

（3）当主动结构中含有情态动词时，改变成被动语态时是由“情态动词＋动词be 原形＋过去分词”构成。

e.g. You must finish your homework in time.

→Your homework must be finished in time.

You can take it home. →It can be taken home.

（5）跟主动结构一样，被动结构也有许多种时态。

1．一般现在时的被动语态构成：is/am/are＋及物动词的过去分词

I am not allowed to go swimming today.

Roads are built by workers every year.

2．一般过去时的被动语态构成：was/were＋及物动词的过去分词

The bridge was completed last year.

Many trees were planted on the hill over there by us.

3．一般将来时的被动语态构成：will＋ be＋及物动词的过去分词

A new library will be built in our school.

The cat will be sent to my uncle’s home.

4．现在完成时的被动语态构成：has / have＋been＋及物动词的过去分词

Lu Xun’s works have been translated into many languages.

2．What are they used for? 它们是做什么用的？

use 使用，用，利用

e.g. What do you use this tool for? 这个工具用途是什么？

use…to do…用……做……

e.g. We use the knife to peel the apples. 我们用小刀削苹果皮。

The bag is used to carry the books. 包是用来运书的。