英语变被动语态

英语变被动语态

13Thousands of trees are cut down by them every year.

1. 定义:被动语态,即不知道动作执行者或强调动作承受者的一种语态。例如中文常说:我被他打,这就是一种被动。但有时由于句子结构上的需要也要用被动,例如it is not unusual for workers in that region to be paid more than a month it 在句中作形式主语。而不定式to be paid more than a month是句子的逻辑主语。结合选项全句的意思是:“那个地方的工人一个多月后才得到工资是常有的事”。 2. 构成:be+past participle(过去分词)(简称p.p.)(+by+动作执行者)(过去分词的概念见上课) 3. 当主动语态要被改成被动的时候,我们把原句的宾语提前,作为改句的主语,主语后置,作为宾语。因此有一点要注意,不及物动词由于不加宾语,没有被动形式,但不及物动词如果与某些介词构成介词短语,可以用被动。例如the fire had been put out before the fireman arrived. put是不即物动词,但put out是及物动词 4. 应用到各种时态和句型如下: ① 一般式(一般现在,一般过去,一般将来):am, is, are, was, were, is going to be , will be+done.ie. once environmental damage is done, it takes many years for the system to recover. 本句的意思是:“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”的含义,do damage的意思是“造成破坏”。主语damage是及物动词do的动作对象,谓语应当用被动语态。同样的,还有,i will mend the machine.相当于the machine will be mended (by me). ② 进行时(现在进行、过去进行、将来进行):be+being+p.p. ie.the classroom is being cleaned. ③ 完成时(现在完成、过去完成、将来完成):have/has been + p.p.:例如the machine will have been repaired by 3 o’clock this afternoon.再如:my homework has been finished. ④ 其他时态依词类推,可得到结果。 ⑤ 情态动词的被动语态:主语 + 情态动词 + be动词 + 动词过去分词,例如your teeth must be brushed. ⑥ 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.(确定超过接待能力的预定时必须考虑预定了房间却来不了的客人。) ⅱ、主动语态变为被动的几个特殊情况 ① 有些动词在主动结构中,后面接不带to的不定式,但如果改为被动,则需把省略的to加上,这类动词有hear, watch, make, help, let等,如:the boss made my grandfather work 10hours a day.改成my grandfather was made to work for 10 hours a day.