动词时态
1. 目前完成进行时态 : 动作或状况从过去某时开始,继续到目前,可能继续下去,也会刚刚结束.
e.g.
1) I’ve been writing letters for an hour.
2) I’ve been sitting in the garden.
2. 过去完成进行时: 过去某个时刻以前一直在进行的动作
e.g.
1) I’d been working for some time when he called.
2) We had been waiting for her for two hours by the time she came.
3. 以后完成进行时: 以后某个时刻以前一直在进行的动作.
e.g.
1) By next summer, he will have been working here for twenty years.
2) In another month’s time she’ll have been studying here for three years.
4. 以后完成时: 以后某时会业已发生的事.
1) I shall have finished this one before lunch.
2) They’ll have hit the year’s target by the end of October.
动词汇态
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实行者。被动语态表示主语是动作的承受者，即行为动作的对象。
对中国的英语学习者来讲，难题一般是被动语态，因此大家今天主要解说被动语态。
被动语态，即不了解动作实行者或强调动作承受者的一种语态。在英语中，假如想要防止用含混不清的词（如someone）做主语，也可以用被动语态。英语的语态是通过动词形式的变化表现出来的。
句型概述
1. 一般以后时：am, is, are, was, were, is going to be , will be+done .
e.g.
once environmental damage is done, it takes many years for the system to recover.
环境一旦遭到破坏，需要多年时间才能恢复过来。
do作为及物动词有“引起，产生”的意思，do damage的意思是“导致破坏”。主语damage是及物动词do的动作对象，谓语应当用被动语态。
其他时态以此类推，可得到结果。
2. 情态动词的被动语态：主语 + 情态动词 + be动词 + 动词过去分词，比如Your teeth must be brushed.
3. 不定式的被动语态：to be done例：The no-shows have to be considered when deciding the rate of overbooking.（确定超越接待能力的预定时需要考虑预定了房间却来不了的客人。
特殊状况
1. 有的动词在主动结构中，后面接不带to的不定式，但假如改为被动，则需把省略的to加上，这种动词有let, make, have, help和感官动词 feel, see, hear, watch,l ook at, listen to等。
e.g.
The boss made my grandfather work 10hours a day.
要改成My grandfather was made to work for 10 hours a day.
2. 含有宾语从句的主动结构变为被动，一般用it作为被动结构的先行主语，从句放在句子后面/也可使用另一种形式，这种动词有：know, say, believe, find, think, report等
3. 不是所有些主动句都可以变换成被动句，更不是所有些被动句都可以自由变换成主动句。虽然语法原则上允许主动和被动句的互相转换，但有些句子转换后会变成不通顺或不地道的英语句子。因此，在某些题目里，这也成为判断应该用主动还是用被动的依据。
e.g.
At 5:05 p.m. on Saturday 19th July , there was an accident at the junction of the Main Street and Panda Road when a boy was knocked down off his bicycle by a delivery van. The boy was sent to St. Maria Hospital where he was treated for shock and a broken arm.
在这段文章里，a boy was knocked down off his bicycle by a delivery van这句被动句强调出读到文章的人最关心的事故的受害者。The boy was sent to St. Maria Hospital这句话则说明了孩子被送到医院的事实，至于是由哪个（某个过路人？或肇事司机？）送的无关紧要。he was treated for shock and a broken arm这句被动句无须说出treat这个动作的发出者，由于在医院，伤病员自然由医务职员处置，无须啰嗦。如此，这段文章就重点突出，条理了解了。
4. 有的动词可以有两个宾语，在用于被动结构时，可以把主动结构中的一个宾语变为主语，另一个宾语仍然保留在谓语后面。多是把间接宾语变为主语。如此句子自然些。直接宾语变为主语时，间接宾语要变为某个介词的宾语，介词to可以省略。如His father left him this house.改为This house was left him by his father.
5. 有的动词虽为及物，但宾语并不是是动作承受者，不可以转换，这类动词有have, hold（容纳）,suit, fit, lack, become（合适）contain, cosplayt, last, mean, suffice（足够）等。
6. 当直接宾语为反身代词、相互代词或宾语前有指代主语的物主代词时不需要被动，如I shook my head.我摇摇头。
7. 当宾语为同源宾语（与主句指同一人），动名词，动词不定式或一个从句时不需要被动。如John enjoyed seeing the film.
8. 在一些固定说法中，有的名词和动词结合的固定说法，不可以改We Chinese always keep our word.
9. 某些从不及物动词转化来的及物动词，直接宾语在表示动作的方法或成效时，这类动词在乎思上起状语有哪些用途，没被动The girl kissed her boyfriend good night=The girl said good night to her boyfriend by kissing him. Our classroom is cleaned everyday.
2) I am asked to study hard.
3) 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
e.g. 1) A new shop was built last year.
2) Dinosaur eggs were laid long long ago.
3.目前完成时的被动语态构成：has/ have + been +及物动词的过去分词
e.g.
1) This book has been translated into many languages.
2) Many man-made satellites have been sent up into space by many countries.
4.一般以后时的被动语态构成：will/ shall+ be + 及物动词的过去分词
e.g.
1) A new hospital will be built in our city.
2) 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
e.g.
1)Young trees must be watered often.
2) Your mistakes should be corrected right now.
3) The door may be locked inside.
4) Your homework can be handed in tomorrow.
6.目前进行时的被动语态构成：am /is /are + being +及物动词的过去分词
e.g.
1) Uncle Wang is mending my bike now.→ My bike is being repaired by Tom now.
2) 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
e.g. There are two books to be read. → There are twenty more trees to be planted.
8.过去以后时的被动语态：would / should+ be + 及物动词的过去分词
e.g.
1) He said he would finish the work soon.
2) He said the work would be finished soon by him.
需要注意的地方
1.不及物动词无被动语态。
The dinosaurs disappeared about 65 million years ago.
2.有的动词用主动形式表示被动意义。这类动词主语以物居多，谓语动词一般表示主语的性质和特点。这种动词有很多，如: write, break, sell等。
e.g. 1) This pen writes well.
2) This new book sells well.
3.感官动词或使役动词用省略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 。
感官动词有smell, sound, taste,fell等。
使役动词有let, make, have, help, hear, see, watch, notice, look, listen等。
e.g.
1) Make somebody do something. → somebody+ be +made to do something
2) 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.
His mother gave him a present for his birthday.→ He was given a present by his mother for his birthday.
4.若是接双宾语的动词改为被动语态时，直接宾语作主语，那样动词后要用介词，这个介词是由与其搭配的动词决定。
e.g.
1) He gave me a book.→ A book was given to me by him.
2) He showed me a ticket.→ A ticket was shown to me by him.
3) 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，而不可以扔掉其中的介词或副词。
e.g.
1) We can't laugh at him. → He can’t be laughed at by us.
2) He listens to the radio every day. → The radio is listened to by him every day.
3) The nurse is taking care of the sick man. → The sick man is being taken care of by the nurse.
6.一些表示状况的动词没被动语态。如：have, belong to等。
