一、被动语态
被动语态的基本结构为：be+动词的过去分词
各种时态的主动、被动语态的结构如下表（以动词do为例）：
时态 主动语态 被动语态 例句
主动语态 被动语态
一般现在时 do/does am/is/are+done We clean the classroom.． The classroom is cleaned by us．
一般过去时 did was/were+done He made the kite． The kite was made by him．
现在进行时 am/is/are+doing am/is/are+being done She is watering flowers． Flower are being watered by her ．
现在完成时 have/has+done have/has+been done Jim has finished the work． The work has been finished by Jim．
一般将来时 will/shall/be going to+do will/shall/be going to+be done They will plant trees tomorrow． Trees will be planted by them tomorrow．
过去进行时 was/were+doing was/were+being done She was writing a letter this time yesterday． A letter was being written by her this time yesterday．
过去完成时 had+done had+been done Jim had finished the work． The work had been finished．
过去将来时 would/should/be going to+do would/should/be going to+be done He said he would make a kite． He said a kite would be made by him．
含有情态动词 can/may/must+do can/may/must+be done I can find him． He can be found by me．
一．被动语态的用法：在被动语态中，主语是动作的承受者，主要用于下列几种情况：
（1）不知道动作的执行者是谁。如：This watch is made in China．更多资料QQ378459309制作：
（2）没有必要指出动作的执行者是谁。如：More trees must be planted every year．。
（3）需要强调或突出动作的承受者时。如：Chinese is spoken by more and more people in the world．
（4）句子的主语是动作的承受者。如：Many houses were washed away by the food．
二、主动语态和被动语态的转换
1．主动语态变为被动语态
（1）要将主动句里的宾语变为被动句中的主语，若主动句中的宾语是人称代词，要将宾语变成主格。
（2）把主动句中的主语变为被动句中的宾语，主格变成宾格，并用by引导。
（3）谓语动词变成相应的被动形式。
主动语态： 动作执行者+谓语动词主动形式+动作承受者
被动语态： 动作承受者+谓语动词被动形式+动作执行者
如：We asked him to sing an English song．(变为被动语态) →He was asked to sing an English song by us．
2．带双宾语的谓语动词变为被动语态
谓语动词带双宾语时，既可以将间接宾语转化成主语，也可以将直接宾语转化为主语。若将间接宾语转化为主语，则保留直接宾语；若将直接宾语转化为主语则保留间接宾语，且在被保留的间接宾语前加上介词to或for。如：She gave me a book．(变为被动语态) →I was given a book by her．(间接宾语me改为了主语)
A book was given to me by her．(直接宾语a book 改为了主语)
3．动词短语变为被动语态
许多由动词和介词、副词构成的动词短语相当于及物动词，可以有宾语，也可以有被动语态。在变为被动语态时，不可丢掉构成动词短语的介词或副词。如：We should speak to old men politely．(变为被动语态)
Old men should be spoken to politely．(to不可省略)
4．带复合宾语的动词变为被动语态
宾语加上宾语补足语一起构成复合宾语。变被动语态时，只把宾语变为被动句的主语，宾语补足语保留在原处，成为主语补足语。如：I heard Jane playing the piano in her room．(变为被动语态) →Jane was heard playing the piano in her room．
5．变被动语态后动词形式的选择
主动句中在感官动词see，hear，watch，feel，notice等，及使役动词let，make，have等后跟省略to的不定式，变为被动句时，应加上不定式符号to。如：He makes the girl stay at home．（变为被动语态）→The girl is made to stay at home by him．