初中英语知识点：被动语态

初中英语知识点：被动语态第三十九课时    被动语态（一）教学重点被动语态在英语中，须通过动词的某种形式来表明句子的主语是动作的执行者还是动作的承受者，前一种句子是主动句，后一种是被动句。英语的动词有两种语态形式，即主动语态和被动语态。如果主语是动作是执行者，谓语动词用主动语态。如果主语是动作的对象，谓语动词用被动语态。如：They build this school.They school is built by them.1、被动语态的构成“助动词 +（及物动词的）过去分词”构成动词被动语态的形式。助动词be有人称、数和时态的变化，其变化规则与be作为系动词的变化完全一样。如：This kind of TV set is made in Guangzhou.（一般现在时）The thief was arrested.（一般过去时）A new road is being built outside my house.（现在进行时）The man was being questioned by the police.（过去进行时）Your wallet has been found.（现在完成时）By the time we got there. The work had been finished.（过去完成时）My sister would be taken care of by grandma.（过去将来时）Your watch will be repaired.（一般将来时）教学难点：在英语里，有一些动词是不及物动词，后面不能跟宾语，所以没有被动语态。以下动词只有主动语态，没有被动语态。appear, die, happen, fall, arrive.2、五种时态的被动语态举例① 一般现在时A lot of books are kept in our school library.Radio is used in everyday life.② 一般过去时A thief was caught last night.They were asked to speak at the meeting.③ 现在进行时A new library is being put up in their school now.The watch is being repaired.④ 一般将来时The class meeting will be held next Saturday afternoon.The thieves will be arrested.⑤ 现在完成时My bag has been stolen.Many stamps have been collected by me since last year.3、主动语态变被动语态① 主动结构的宾语变为被动结构的主语。② 主动结构的谓语动词由主动语态变为被动语态。③ 主动结构的主语变为介词by的宾语，组成介词短语，放在被动结构中谓语动词之后。在动作的执行者无须说明或不必强调时，by短语可以省略。④ 主动语态、被动语态两种时态要保持一致。如：We repaired the motor.The motor was repaired by us.第四十课时    被动语态（二）教学重点被动语态（二）几种不同形式的被动语态（1）含有直接宾语和间接宾语的主动结构，变为被动结构时，可以将其中一个宾语变为主语，另一个不动，一般是主动结构的间接宾语变为被动结构的主语，这样句子显得自然一些。如：He showed me his pictures.I was shown his pictures by him.I was sent a birthday present (by him).A birthday present was sent to me (by him).（2）含有复合宾语的主动句变为被动句的方法。① 将宾语变为主语，宾语补足语保留不动。如：They call her little Li.   She is called little Li.He left the door open.   The door was left open by him.② make, let, hear, watch, see, feel, have, notice, help等动词后面作宾语补足语的不定式一般不带to，可是当变为被动语态时，后面的不定式必须带to。如：My brother often made me do this and that when I was young.I was often made to do this and that by my brother when I was young.③ 含有情态动词的被动语态，是由“情态动词 + be +（及物动词的）过去分词”构成。如：They can not find him.He can not be found.④ 短语动词的被动语态一般说来，只有及物动词才有被动语态，因为只有及物动词才可能有动作的承受者。但有许多由不及物动词加介词及其他词类构成的短语动词，相当于及物动词，可以有宾语，因而也可以有被动语态。但应注意，短语动词是一个不可分割的整体，在变为被动语态时，不可丢掉构成短语动词的介词或副词。如：They had put out the fire before the fire brigade arrived.The fire had been put out before the fire brigade arrived.They will set up a new public school here.A new public school will be set up here.You must take good care of these trees.These trees must be taken good care of.被动语态的基本用法① 不知道谁是动作的执行者或者没有必要指出谁是动作的执行者时。如：Paper is made from wood.The house is quite old, it was built in 1950.He was wounded in the fight.② 需要强调动作的承受者时。如：Calculator can’t be used in the maths exam.Books and newspapers in the reading room mustn’t be taken away.He was awarded first prize in that contest.③ 为使语气婉转，避免提及自己或对方而使用被动语态，或由于修辞的需要使用被动语态使句子得以更好安排。如：The construction of the new lab must be completed by the end of next month.Electricity is used to run machines.