语态是动词的一种形式,它表示主语和谓语的关系.语态有两种：主动语态和被动语态.如果主语是动作的执行者,或者是说动作是由主语完成的,要用主动语态；如果主语是动作的承受者,或者是说动作不是由主语而是由其他人完成的,则用被动语态.
在英语中的被动语态使用得比汉语要多,要普遍使用,许多课本及考试乃至实际应用中都常常涉及到这个问题.一般说来,当强调动作承受者,不必说出执行者或含糊不清的执行者时,多用被动语态.需要
补充
注意的是,许多地方与汉语不同.注意：哪些汉语中没有“被……的短语往往又不是被动语态,而是主系表结构.还有些特殊现象,如：“known to m的意思,英语却应该用被动态.还要注意,英语的被动态往往由“by”引出,而有用介词“by”on foot”步行（美国人有时用“by foot”）,“in carriage”（乘四轮马车）等等.还有假主动,真被动的十几个常用词的用法,以及“so heavy to carry”而不用“so heavy to be carried”等习惯用法.有关这类情况,做到心中有数对全面掌握被动语态,准确无误地解答习题非常关键,被动态必须涉及的是动词的各种时态变化的问题.英语的时态本来很复杂,怎样记住各自的被动形式呢?首先要明确“将来进行无被动,现在完成进行同”.这两种时态无被动形式.
另外,不及物动词带有同原宾语的动词,反身代词的动词和系动词都无被动形式.即便如此,还有不定式,动名词,分词,以及它们的复合结构的被动态,再加上情态动词,助动词以及它们的疑问式和否定式从中掺杂.下面口诀就以动词“do”为例,即“do、did”过去式“done”过去分词,以口诀形式总结各种时态的被动态.一定对你有所启示. 当然了,被动语态也可以概括为“be done”.
被动语态 （一般现在时）
主动语态变被动语态时,主动语态句中的宾语变成被动语态句中的主语,主动语态句中的主语成为被动语态句中的动作的发出者.
被动语态的口诀：
一般现、过用be +V.过去分词,be有人称、时、数变.
完成时态have（has）done,被动将been加中间.
一般将来shall（will）do,被动变do为be done.
将来进行无被动,shall（will）be doing.
现在完成进行同,have（has）been doing.
现、过进行be doing,被动be加being done.
情、助、有、是妥安排,一律随新主语变.
否定助后加not,疑问一助置主前.
主语恰是疑问词,直陈语序主在前.
一般情助加be done,双宾多将间宾变.
复合宾语宾变主,宾补、主补相应变.
1.一般现在时isamare+P.P（过去分词）
2.一般过去时waswere+P.P
3.一般将来时will be+P.P
4.现在进行时isamare+being（固定不变）+P.P
5.过去进行时waswere+being（固定不变）+P.P
6.现在完成时havehas been+P.P
7.过去完成时had been+P.P
第二句“be有人称、时、数变”即be有人称、时态和单、复数的变化.“情助”是指情态动词和助动词“must,may,can,shall,will”等一律随新主语（多是主动句中的宾语）来变化.“疑问一助置主前”是说有两个助动词的话,应把主语放在第一助动词之后或把第一助动词置于主语之前
一般现在及过去时 一般现在、过去时用be done, be有人称、时态和数的变化
完成时态 “have done”,被动将“been”加中间.
（过去完成时“had done”也包括在内）.
一般将来 “shall (will) do”,被动变“do”为“be done”
将来进行时 将来进行时无被动,shall（will）be doing,
现在完成进行同.have（has）been doing,
特别提醒 有些动词后跟不带to的不定式作宾语补足语,但改为被动结构后要加上“to”.例如
We heard him singing his room just now.
---He was heard to sing in his room just now.
刚才听到他在房间中唱歌.
need doing something也表示被动
一、 被动语态的用法： 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
Our classroom is cleaned everyday.
I am asked to study hard by my mother.
Knives are used for cutting things.
2. 一般过去时的被动语态构成：was / were + 及物动词的过去分词
A new shop was built last year.
Dinosaur eggs were laid long long ago.
3. 现在完成时的被动语态构成：has / have + been + 及物动词的过去分词
This book has been translated into many languages.
Many man-made satellites have been sent up into space by many countries.
4. 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 hospital will be built in our city.
Many more trees will be planted next year.
5. 含有情态动词的被动语态构成：情态动词+ be + 及物动词的过去分词
Young trees must be watered often.
Your mistakes should be corrected right now.
The door may be locked inside.
Your homework can be handed in tomorrow.
6. 现在进行时的被动语态构成：am / is / are + being + 及物动词的过去分词
Uncle Wang is mending my bike now.→
My bike is being repaired by Tom now.
They are planting trees over there. →
Trees are being planted over there by them.
7. 不定式的被动语态：to + be + 及物动词的过去分词
There are two books to be read. →
There are twenty more trees to be planted.
二、 主动变被动的方法 把主动语态改为被动语态非常简单,可以遵循以下几个步骤：
1. 将主动语态的宾语作被动语态的主语；
2. 谓语动词变为“be+及物动词的过去分词”,并通过be的变化来表达出不同的时态；
3. 主动语态的主语变为介词“by”的宾语,组成介词短语放在被动结构中的谓语动词之后.（有时“by”的短语可以省略）；
例：1. Bruce writes a letter every week. →A letter is written by Bruce every week.
2. Li Lei mended the broken bike this morning.→The broken bike was mended by Li Lei this morning.
3. He has written two novels so far.→Two novels have been written by him so far.
4. They will plant ten trees tomorrow.→Ten trees will be planted by them tomorrow.
5. Lucy is writing a letter now.→A letter is being written by Lucy now.
6. You must lock the door when you leave.→the door must be locked when you leave.
三、 特别关注： 1. 不及物动词无被动语态. 如：happen, break down, come out.
What will happen in 100 years.
The dinosaurs disappeared about 65 million years ago.
2. 有些动词用主动形式表示被动意义. 如： write, sell, ride.
This pen writes well.
This new book sells well.
3. 感官动词或使役动词使用省略to的动词不定式,主动语态中不带“to”,但变为被动语态时,须加上“to”.
例：make somebody do something→somebody+ be +made to do something
see somebody do something→somebody +be +seen to do something
A girl saw my wallet drop when she passed by.→My wallet was seen to drop by a girl when she passed by.
The boss made the little boy do heavy work.→The little boy was made to do heavy work by the boss.
4. 如果是接双宾语的动词改为被动语态时,直接宾语（物）作主语,那么动词后要用介词,这个介词是由与其搭配的动词决定.
He gave me a book.→A book was given to me by him.
He showed me a ticket.→A ticket was shown to me by him.
My father bought me a new bike. →A new bike was bought for me by my father.
5. 一些动词短语用于被动语态时,动词短语应当看作一个整体,而不能丢掉其中的介词或副词.
We can’t laugh at him. →He can’t be laughed at by us.
He listens to the radio every day. →The radio is listened to by him every day.
The nurse is taking care of the sick man. →The sick man is being taken care of by the nurse.
构成
be+done.
现在完成时的结构 现在完成时由“have/has+过去分词”构成,主要有两个含义：
①表示动作发生在过去,但与现在的情况有联系,有时无时间状语,有时和一些表示不确定的过去时间状语连用,如：many times,just,yet,ever,never,already,before,so far, by now等连用.
②表示从过去某一时间开始一直延续到现在并还可能继续延续下去的动作,用于延续性动词,且句中常带有表示一段时间的时间状语,如：since + 时间点/从句,for two months, so far等.
二 、1）现在完成时和一般过去时都能表示过去发生过的动作,但现在完成时表示过去动作对现在的影响,并且表示这一动作已完成或还可能继续下去；2）而一般过去时与现在的情况没有联系,仅表示过去的动作,且这一动作到说话时已终止.因此现在完成时不能与表示明确的过去时间如：in1949,yesterday,last week等的状语连用,并且用when或where对这些时间和地点状语提问时,一般只用一般过去时.
三、在“it is first/second...time that.”或在“it/this/that is the +最高级+名词+that.”结构中,that从句中的动词常用现在完成时；在“it + be ...+since从句”这一结构中,be可用一般现在时或现在完成时,since从句一般用过去时.have/has/had +been +动词的现在进行时
比较过去时与现在完成时 1）过去时表示过去某时发生的动作或单纯叙述过去的事情,强调动作；现在完成时为过去发生的,强调过去的事情对现在的影响,强调的是影响.
2）过去时常与具体的时间状语连用,而现在完成时通常与模糊的时间状语连用,或无时间状语.一般过去时的时间状语:
yesterday, last week,…ago, in1980, just now, 具体的时间状语
共同的时间状语:
this morning, tonight, this April, now, once,before, already, recently,lately
现在完成时的时间状语
for, since, so far, ever, never, just, yet, till / until, up to now, in past years, always,
不确定的时间状语
3）现在完成时可表示持续到现在的动作或状态,动词一般是延续性的,如live, teach, learn, work, study, know.
过去时常用的非持续性动词有come, go, leave, start, die, finish, become, get married等
用于现在完成时的句型 1）It is the first / second time…. that…结构中的从句部分,用现在完成时.
It is the first time that I have visited the city.
It was the third time that the boy had been late.
2）This is the… that…结构,that 从句要用现在完成时.
This is the best film that I've (ever) seen.
这是我看过的最好的电影.