【语法详解】被动语态
㈠英语中的语态－主动语态和被动语态
⒈英语动词有两种语态：主动语态和被动语态。主动语态表示主语是动作的执行者，被动语态表示主语是动作的承受者。如：①They built a new bridge over the river. (主动) A new bridge was built over the river by them. (被动) ②Many people speak English. (主动) English is spoken by many people. (被动)
⒉汉语中常用“被”、“给”、“由”、“受”等词用来表示被动，而英语用“助动词be＋及物动词的过去分词构成”，即“be＋p.p.”，其中助动词be有人称、数和时态的变化。
㈡被动语态的基本用法
⒈当句子的主语是动作的执行者时，谓语的形式是主动语态。当句子的主语是动作的承受者时，谓语要用被动语态。被动语态由助动词be＋过去分词构成，时态通过动词be表现出来。
⒉什么时候使用被动语态
⑴不知道或没有必要说明动作的执行者是谁。
①Some windows were broken last night. ②This book was published (出版) in 2005.
注意：第②句＝This book came out in 2005. come out 是不及物动词短语，不能用于被动语态。
⑵只强调动作的承受者，而不强调动作的执行者。
①Educational CD-ROMs are sold in many countries. ②Rice was first grown in China.
③English is learned all over the world.
注意：不及物动词或不及物动词短语无被动语态，如：appear, happen, take place等。
㈢被动语态的基本结构
⒈动作的承受者＋be＋过去分词＋其他＋by＋动作的执行者。
简写为“承受者＋be＋过去分词＋其他＋by＋动作的执行者”。
⒉主动语态变为被动语态的步骤：
确定主动语态的时态，它决定着被动语态中的助动词be。 找出主动语态的主、谓、宾。
按照上述句式改写：承受者 +be+过去分词+其他＋by＋执行者
⒊常用的被动语态结构
时态 结构 时态 结构
一般现在时 am/is/are＋p.p. 含情态动词 can/may/must/… be＋p.p.
一般过去时 was/were＋p.p. 现在完成时 have/has been + p.p.
一般将来时 will/shall be＋p.p.
am/is/are going to be＋p.p. 现在进行时 am/is/are being + p.p.
⒋主动改为被动语态的例子：主动语态基本结构为主、谓、宾。
⑴His brother washes dishes every day. Dishes are washed every day by his brother.
主(执行者) 谓 宾(承受者) 其他
⑵Peter will clean the room tomorrow. The room will be cleaned tomorrow by Peter.
⑶He must look after the little boy. The little boy must be looked after by him.
⑷The students are watching a charity show. A charity show is being watched by the students.
㈣特殊情况的被动语态
简单句五种基本形式中的其中两种变为被动语态时十分重要：
⒈主谓＋双宾：这类短语含有介词to或for。如：give, send, show, buy, make…
⑴give sb sth＝give sth to sb，buy sb sth＝buy sth for sb
主动语态：Amy gave me some nice stickers.＝Amy gave some nice stickers to me.
被动语态：I was given some nice stickers by Amy.或Some nice stickers were given to me by Amy.
⑵主动：A fairy gave the princess a magic wand.＝A fairy gave a magic wand to Princess Laura.
被动：The princess was given a magic wand by a fairy.或A magic wand was given to the princess.
总结含有双宾语的动词短语变为被动语态的规则：可以把任何一个宾语作为被动语态的主语；如果把直接宾语(即物体)作为主语，动词和直接宾语之间要添加相应的介词to或for。主动语态中无论使用give sb sth 还是give sth to sb，一律按照上述句子改写，即：
give sb sth 或give sth to sb sb be given sth或sth be given to sb，这类含有介词to或for的短语见下表
主动语态 被动语态
send sb sth或send sth to sb sb be sent sth或sth be sent to sb
show sb sth或show sth to sb sb be shown sth或sth be shown to sb
buy sb sth或buy sth for sb sb be bought sth或sth be bought for sb
make sb sth或make sth for sb sb be made sth或sth be made for sb
⒉主谓宾＋省略to的不定式(即宾补)：使役动词变为被动语态时，原来省略的to一定要加上。
常见短语⑴make sb do sthsb be made to do sth (主动语态不含to，被动语态必须带to。下同)
⑵hear sb do sthsb be heard to do sth
⑶see sb do sthsb be seen to do sth
⑷have sb do sthsb be had to do sth
注意特殊例子：let sb do sth sb be let do sth (主动语态和被动语态都不含to。)
e.g. He made the workers work 12 hours a day. The workers were made to work 12 hours a day.
㈤主动形式表示被动意义：有些不及物动词(其主语大都指物)的主动语态可以表示被动意义。
⒈某些连系动词。这些动词有feel, taste, smell, sound, prove等。
①The coffee smells delicious. ②The story proved quite false.
⒉某些可与well, easily, quickly等副词连用的不及物动词。
①This kind of bikes sells well. ②This kind of rice cooks more quickly than that kind.
⒊某些可用于“主＋谓＋主补”结构中的不及物动词。e.g. The bag broke open.
⒋动名词在be worth doing句型中的主动形式表示被动含义。
①His novels are so well worth reading that I want one. ②These stamps are worth collecting.
⒌动名词在need, want, require等动词后，主动形式表示被动含义。need doing＝need to be done
①The problem requires dealing with immediately. ②Her bike needed repairing.
⒍动词不定式的主动形式在too…to…句型中表示被动含义。The box is too heavy to carry.
⒎有些形容词后的动词不定式有被动含义。这些形容词有easy, difficult, heavy, nice, good, pleasant, important, useful, dangerous等。
①Bad habits are easy to contract. ②English is difficult to learn.