英语动词时态和语态语法复习二

二、被动语态：英语动词的语态有两种：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，在被动语态的句子中，动作的执行者，一般由介词by引起的短语来表示，如:We often help them. (主动)我们常帮助他们。They are often helped by us.(被动)他们常被我们帮助。
1、被动语态各时态的形式是由助动词be的各时态的形式加及物动词的过去分词构成。
2、被动语态八种时态的用法例句:被动语态常用的八种时态的基本用法和主动语态各时态的
基本用法相同，只是句中的主语不是动作的执行者，而是动作的承受者，如:
(1)一般现在时：Now English is taught in all middle schools in our country.
(2)一般过去时：The Great hall of the People was built in 1959.
(3)一般将来时: When will the work be finished?
(4)过去将来时：He told us that the work would be finished the next day.
(5)现在进行时： Your tractor is being repaired now.(6)过去进行时：
The child was being examined by the doctor when they came in.
(7)现在完成时： The work hasn’t been finished yet.
(8)过去完成: The new plan had been carried out before the second experiment began.
3、在下列情况下，一般使用被动语态：（1）当不知道动作执行者是谁或没有必要提到动作执行者时，如：Paper was first made in China. （2）当强调或突出动作承受者的作用时，如：The new machine was invented by a 20-year-old young worker.