九年级的英语主动语态转被动语态怎么变啊,老师讲的没明白呢

一、语态概述
英语的语态是通过动词形式的变化表现出来的.英语中有两种语态：主动语态和被动语态.
主动语态表示主语是动作的执行者.巧记为：主动、主动、主去动.

例如：Many people speak English.
谓语：speak的动作是由主语many people来执行的.
被动语态表示主语是动作的承受者,即行为动作的对象.巧记为：被动、被动、主被动.例如：English is spoken by many people.主语English是动词speak的承受者.
主动态和被动态指的是动词形式,是词法概念；而主动句和被动句则指的是句子结构,从而是句法概念.所谓主动句就是由主动态动词(词组)作谓语动词的句子,而被动句则是由被动态动词(词组)作谓语动词的句子.
例如：He opened the door.他开了门.(主动句)
The door was opened.门被开了.(被动句)
二、被动语态的构成
被动语态由“助动词be＋及物动词的过去分词”构成.人称、数和时态的变化是通过be的变化表现出来的.现以teach为例说明被动语态在各种时态中的构成.
一般现在时：am／is／are＋taught
一般过去时：was／were＋taught
一般将来时：will／shall be＋taught
现在进行时：am／is／are being＋taught
过去进行时：have／has been＋taught
现在完成时：have／has been＋taught
歌诀是：被动语态be字变,过去分词跟后面.
三、被动语态的用法
(1)不知道或没有必要说明动作的执行者是谁.
例如：
Some new computers were stolen last night.
一些新电脑在昨晚被盗了.(不知道电脑是谁偷的)
This book was published in 1981.这本书出版于1981年.
(2)强调动作的承受者,而不强调动作的执行者.
例如：the window was broken by Mike.窗户是迈克打破的.
This book was written by him.这本书是他写的.
Eight hours per day for sleep must be guaranteed.每天8小时睡眠必须得到保证.
歌诀：谁做的动作不知道,说出谁做的没有必要；
动作承受者需强调,被动语态运用到.
四、主动语态变被动语态的方法
(1)把主动语态的宾语变为被动语态的主语.
(2)把谓语变成被动结构(be＋过去分词)
(根据被动语态句子里的主语的人称和数,以及原来主动语态句子中动词的时态来决定be的形式).
(3)把主动语态中的主语放在介词by之后作宾语,将主格改为宾格.例如：
All the people laughed at him.
He was laughed at by all people.
They make the bikes in the factory.
The bikes are madeby themin the factory.
歌诀是：宾变主,主变宾,by短语后面跟.
谓语动词变被动,be后“过分”来使用.
五、含有情态动词的被动语态
含有情态动词的主动句变成被动句时,由“情态动词＋be＋过去分词”构成,原来带to的情态动词变成被动语态后“to”仍要保留.
歌诀是：情态动词变动,情态加be加“过分”,原来带to要保留.例如：
We can repair this watch in two days.
This watch can be repaired in two days.
You ought to take it away.
It ought to be taken away.
They should do it at once.
It should be done at once.
1.主动语态变为被动语态,主词变为介系词by的受词,受词变为主词,人称代名词的格也要变化.
Peter, I heard he was hit by you. (被)
Peter, I heard you hit him. (主)
彼得,我听说你打了他.
I hit him.(主)
He was hit by me. (被)
我打了他.
2.主动语态变为被动语态,句子的时态保持不变.
I will give him a pen.(主)
He will be given a pen by me.(被)
我将给他一支笔.
3.一些与格动词的被动语态有两种形式;另一些与格动词如：write, make, bring等的被动语态则只能以直接受词作主词.
A toy was given to Tom by me. (被)
Tom was given a toy by me. (被)
I will give Tom a toy. (主)
我给汤姆一个玩具.
Tom gave me a pen.(主)
A pen was given to me by Tom.(被)
I was given a pen by Tom.(被)
汤姆给我一枝笔.
A big cake was brought to me by you. (被)
You brought me a big cake. (主)
你带给我一个大蛋糕.
She wrote me a letter.(主)
A letter was written to me by her.(被)
她给我写了一封信.
write当述语动词,在此只能用直接受词letter当被动语态的主词.
4.在感官动词或使役动词后作补语的原形动词,在被动语态中用不定词.
You were heard to talk with Peter. (被)
I heard you talk with Peter. (主)
我听到你和彼得谈话.
I saw her come out of the classroom.(主)
She was seen to come out of the classroom by me.(被)
我看见她出了教室.
5.主动语态中如用people, somebody等作主词,被动语态中可省略受词.
People eat watermelons in the summer.(主)
Watermelons are eaten in the summer.(被)
在夏天吃西瓜.
6.否定句的被动语态中,not放在第一个助动词后.
I should not be blamed by you. (被)
You should not blame me. (主)
你不应该责怪我.
You should not write this letter.(主)
This letter should not be written by you.(被)
你不应该写这封信.
7.疑问句的被动语态中,用BE的对应形式代替DO.
Does she drive this car?(主)
Is this car driven by her?(被)
她开这辆车吗?
What shall we do next?(主)
What will be done by us next?(被)
我们下一步做什么?
8.祈使句的被动语态形式为：let+受词+be+过去分词.
Open the door please.(主)
Let the door be opened please.(被)
请开门.
9.主动语态中有复合人称代名词时,被动语态的形式为:主动语态的主词+BE+过去分词.
Tom was hurt. (被)
Tom hurt himself. (主)
汤姆自己受的伤.