语态是动词的一种形式,表示句子中主语和谓语动词的关系,主动语态表示主语是动作的执行者,被动语态表示主语是动作的承受者。只有及物动词才能用于被动语态。
一．被动语态的时态：
1.一般现在时的被动语态：  am /is/ are +动词的过去分词
2.一般过去时的被动语态：  was /were +动词的过去分词
3.一般将来时的被动语态：  will be +动词的过去分词
4.现在进行时的被动语态：  am /is /are +being +动词的过去分词
5.现在完成时的被动语态：  have /has +been +动词的过去分词
6.情态动词的被动语态：   情态动词 + be +动词的过去分词
二．被动语态的基本用法:
(1) 需要强调动作的承受者时
The Great Wall is enjoyed by millions of people all over the world
English is widely spoken in the world now.
 (2) 不知道或没必要指出动作的执行者时
Mr. Wang is invited to the meeting today .
The problem is dealt with now .
(3) 当说话人需要强调客观时
It is said that she was a beauty when she was young .
三．主动主动语态变被动语态的变法：
口诀：宾变主，主变宾，谓变be done ,时不变，数格必须随被变。
  注：1.主动、被动的时态要一致。
      2.主动、被动的句式要一致。
      3.变成的被动语态的主语与谓语在单复数上保持一致。
语态转换不被动语态的步骤
1, 把原主动句中的宾语转换为被动语态的主语
2, 把动词改为被动语态形式即"be+过去分词"。
3, 原来主动语态句子中的主语,如果需要就放在by的后面以它的宾格形式出现(因为by是介词,后面需跟宾格作介词的宾语。)以指明做事的人或物,如果没有必要,可以省略。
4, 其它成分不变
5, 被动语态中"by+宾语"的省略
被动语态句式中的"by+宾语"表示及物动词所表示动作的执行者,但是在遇到以下情况时,表示动作执行者"by +宾语"常常被省略。
(1) 动作执行者不确定时
Paper is made from wood .
Many people are killed in traffic accidents every year .
(2) 不必表明动作执行者时
English is also spoken as the second language as well as one of the official languages
Football is played in most schools。
(3 ) 动作执行者为一般大众时
Both English and Spanish are spoken in this area.
一般过去时的被动语态的基本句式
(1) 肯定式:主语+ was /were +过去分词+by
It was made in Beijing Ren'ai Education Institute .
 (2) 否定式:主语+was /were + not + 过去分词+ by
She was not given a paniting by him .
This question was not discussed at the meeting yesterday .
(3) 一般疑问句:Was /Were + 主语+过去分词+by ?
Was it made of bamboo?
(4) 特殊疑问句:特殊疑问词+was/were + 过去分词+by
What was is made of ?
教你一招
如果句子为一般现在时,主动语态用do/does ,被动语态用is/am /are
如果句子为一般过去时,主动语态用did ,被动语态用was /were .
由情态动词构成的被动语态的基本句式
(1) 肯定式:主语+情态动词+be+ 过去-Water can be changed into ice.
She ought to tidy up her bedroom----Her bedroom ought to be tidied up.
You should buy a dictionary at once ----A dictionary should be bought at once by you.
(2) 否定式:主语+ 情态动词+not +be +过去分词+by
You must not take out any books .- Any books mustn't be taken out by you .
They needn't look after the little child ----The little child needn't be looked after (by them)
(3) 疑问句:情态动词+主语+be +过去分词+by
Can you use it ?------Can it be used ?
常见的情态动词有:can,may, ought to, must , dare , need,should.
主动语态不能变为被动语态的情况:
1, 当宾语是反身代词时 The man introduced himself as Mr.Parker .
2,当谓语是表示状态的及物动词时 Does the pair of new shoes suit you?
We will have a meeting .
四．特殊情况的被动语态：
1.带双宾语的被动语态：
动词+ sb(间宾) +sth(直宾)
口诀：如遇双宾语，一般变间宾，若把直宾变，to /for 间宾连。
1).give/pass /show 与介词to 搭配。
give sb sth —— sb +be given sth 或 sth +be given +to sb .
2).buy/make/cook 与介词for 搭配。
buy sb sth —— sb +be bought + sth 或 sth +be bought +for sb
He gave me a book
I ______ ______ a book by him.
A book ____ ____ _____ me by him .
My mother made me a cake .
I ____ _____ a cake by my mother
A cake ____ ____ ____ me by my mother .
2.带省to 的不定式作宾补的被动语态：动词+ sb + do sth .
口诀：感使动词真叫怪，to来to去记心怀，主动语态to离去被动语态to回来。
动词：make / let /have /see /hear /feel /watch
make sb do sth ----sb + be +made +to do sth
The boss made the workers work all day
The workers ____ ____ ____ work all day by the boss.
3. see /hear /notice /keep +sb +doing sth 句型中变被动语态时doing 不变。
I heard Tom singing just now  Tom _____ _____ _____ by me just now .
4.以动词短语作谓语的主动语态变被动语态时，不可丢掉后面的介词或副词。
We should take care of the old .  The old should ______ _____ _____ _____ .
五．注意事项：
1.有些及物动词或动词短语不能用于被动语态：
last ,have ,own …..belong to ,suit…fine ,
2.不及物动词是没有被动语态：
happen ,take place ,appear , hold (容纳)
3.系动词是没有被动语态：Look, feel ,sound ,smell ,taste ….
The dish tastes good .
4.有些词组没有被动语态：sell well , write well ,ride well ,drive well
This kind of skirt sells well.
5.need表示需要时，后面常接doing 形式表示被动意义，相当于to be done .
All the computers need repairing .=
All the computers need _____ _____ _____ .
6.在too…to…及enough to …结构中有时表示被动意义。
The problem is too difficult to solve.