III.被动语态的用法
被动语态表示句子的主语是动作的承受者，也就是动作的对象，一般说来只有及物动词才有被动语态。其构成为"be+及物动词的过去分词"。助动词be有人称、数和时态的变化，其变化规则与be作为连系动词时完全一样。含有情态动词的谓语变化为被动语态时，由"情态动词(can, may must, have to等)+be +动词的-ed形式。含有"be going to , be to, used to, be about to"等结构的复合谓语变为被动语态时，其构成为"be going to (be to, used to, be about to)+ be +动词的-ed形式"构成。
1.被动语态的适用范围
①当我们不知道谁是动作的执行者，或者没有必要指出谁是动作的执行者时。这时不用by短语。
This jacket is made of cotton. 这件上衣是棉料的。
②为了强调动作的承受者时
Visitors are requested not to touch the exhibits. 要求参观者不可触摸展品。
③出于策略、委婉、礼貌等不提出动作的执行者
You are said to be active recently. 据说你最近很活跃。
常用于如下句型：
It's not known that… ……不得而知 It's said that… 据说……
It's reported that… 据报道…… It's not decided that…尚未决定
It's believed that… 据认为…… It's announced that…据宣布……
2.被动语态的句型
①常见句式是：主语(受动者)+be+过去分词+(by+施动者)
He was scolded by the English teacher.
②主语+get+过去分词+其它成分
The boy got drowned last summer./ She got fired because of her faults.
使用这种结构不能带有“by+施动者”
在现代英语中大量地出现了由"get+及物动词的过去分词"构成的被动语态，这就叫做get-型被动语态。get-型被动语态中的过去分词数量有限，通常为单个的动词或比较简单的动词短语。
▲get+及物动词的过去分词
get常同marry, beat, break, damage, tear, strike, hurt, paint, invite, repair, dress, pay, wound等动词的-ed形
式连用，构成被动语态。这种结构一般指动作的结果而非动作本身，常指"最后终于，突然发生"等意义。
He got wounded in the battle. 他在战斗中受伤了。
The boy got hurt on his way home from work. 男孩在回家的路上受伤了。
▲get-型被动语态一般不宜用在含有双宾语的结构中，也不宜与see, hear, watch, listen to等感官动词构成被动语态。
The old man was offered a large sum of money. (正)有人给了这位老人一大笔钱。
The old man got offered a large sum of money. ( 误)
▲get-型被动语态有时有言外之意或具有感情色彩
He got taught a lesson. 他被教训了一顿。(有“活该”之意)
How did the window get closed. 窗户怎么关上了?(有“不该关上’之意)
▲get-型被动语态有时表示开始进入某种状态，而be+动词的-ed形式只表示存在的状态。
She got tired. 她感到累了。(有开始感到疲劳的含义)
She was tired. (只表示”她累了”)
③带有双宾语(直接宾语和间接宾语)的主动句变为动句，其主语可以是直接宾语，也可以是间接宾语。
She lent me a bike.®被动：▲I was lent a bike(by her).
▲A bike was lent to me(by her).
④情态动词+be+过去分词
This problem must be worked out in half an hour.
⑤双重被动式：主语+被动式谓语+不定式的被动式+其它成分
These magazines are not allowed to be taken out of the reading-room.
The murderer was ordered to be shot.
3.主动表示被动的几种情况
①不及物动词与状语连用，用以表示主语的品质和状态
常见动词是：cut,sell,read,write,fill,cook,lock,wash,drive,keep等
This knife cuts well.这把刀好切。
These books sell well.这些书好卖。
The pen writes smoothly.这支笔写起来流畅。
Meat won’t keep long in such hot weather.肉在这样热的天气里放不长久。
The cloth washes well.这种布好洗。
②一些连系动词的主动式+形容词。常见动look,smell,taste,sound,feel,prove,turn out等
The apples taste good.
The flower smells wonderful.
The news proved/turned out true
Cotton feels soft.
4.不可变为被动语态的几种情况
①当句子的宾语是反身代词时(因为反身代词不可作主语)
He can dress himself. 他能自己穿衣服。不可变为Himself can be dressed by him.
②当句子的宾语是相互代词时(因为相互代词不可作主语)
We help each other/one another.不可变为Each other/One another is helped by us.
③动宾结构的固定短语只能用于主动式，不能用被动式
He lost heart.不可变为Heart was lost by him.
类似lose heart词组的还有make a face,keep silence,keep words,lose in thought等等
④take part in,belong to ,own,have,hate,fail,contain等表状态动词没有被动语态
She took part in the sports meet.不能变为The sports meet was taken part in by her.
⑤当have, cost, fit, last, hold等表示状态的及物动词作谓语时
Our village has twenty tractors. 我们村有20台拖拉机。
The hall can hold 2000 people. 这个大厅能盛2000人 The war lasted four years. 这场战争持续了4年 ⑥当某些及物动词(如leave, enter, join,等)的宾语是表示处所、地点或组织时
The students entered the classroom one by one. 学生门陆续地进了教室。
My brother joined the Party two years ago. 我哥哥2年前入了党。
My father left his hometown five years ago. 我父亲5年前离开了家乡。
⑦当句子的宾语是同源宾语时
The Browns live a happy life. 布朗一家过着幸福的生活。
⑧当句子的宾语为行为者(主语)身体上某一部分时
I couldn't believe my eyes when I saw him still alive. 看到他还活着，我简直不相信自己的眼睛。
He hurt his foot by jumping over a fence. 他跨越栅栏时伤了脚。
⑨当用非谓语动词作宾语时
He likes studying English. 他喜欢学习英语
I wish to go there myself. 我想亲自去那里一趟 注意：少数以不定式(短语)做宾语的动词(如agree, feel, decide, think等)可以变为被动句，但不能以不定式(短语)直接做被动句的主语，而要借助it为先行主语，将不定式(短语)置于谓语动词之后 He has decided to go and study abroad.
→It has been decided(by him)to go and study abroad. 他已决定出国留学。
5.含有短语动词在被动语态中介词不能丢
Much attention must be paid to your handwriting.
