1、Unit3 The InternetDiscovering useful structures被动语态被动语态是动词的一种特殊形式,用以说明主语与谓语动词之间的关系,表示主语是动作的承受者。一般来说,只有需要动作对象的及物动词才有被动语态。被动语态由“助动词be+及物动词的过去分词”构成,其时态变化只改变be的形式,过去分词部分不变。be动词+动词过去分词在英语中,被动语态使用得比汉语要多,要普遍,虽然大多数句子都使用主动语态,但被动语态在英语中也是极为重要的,许多课本及考试乃至实际应用中都常常涉及到这个问题。一般说来,当强调动作承受者,不必说出执行者或含糊不清的执行者时,多用被动语态。需要注
2、意的是,许多地方与汉语不同。注意:那些汉语中有“被”的短语往往又不是被动语态,而是主系表结构。还有些特殊现象,如:“known to me的意思,英语却应该用被动态。还要注意,英语的被动语态往往由“by”引出,而有用介词“by on foot”步行(美国人有时用“by foot”),“in carriage”(乘四轮马车)等等。还有假主动,真被动的十几个常用词的用法,以及“so heavy to carry”而不用“so heavy to be carried”等习惯用法。被动语态常用于陈述事实,一般用在科技文章或新闻报道中。口诀 一般现在时、一般过去时用be+及物动词的.过去分词,be有人称
3、、时、数变。完成时态have(has)done,被动将been加中间。一般将来shall(will)do,被动变do为be done。将来进行无被动,shall(will)be doing。现在完成时,被动 have(has)been done。现、过进行be doing,被动be加being done。情、助、有、是妥安排,一律随新主语变。否定助后加not,疑问一助置主前。主语恰是疑问词,直陈语序主在前。一般情助加be done,双宾多将间宾变。复合宾语宾变主,宾补、主补相应变。主动语态变为被动语态例句:一般现在时:主:We believe him.被:He is believed by u
4、s.一般过去时:主:He bought his children some pens.被:Some pens were bought for his children by him.现在完成时:主:He has received the letter.被:The letter has been received by him.现在完成时现在完成时表示过去发生的动作对现在造成影响,或是过去的状态持续到现在。基本结构为:主语+have/has+动词的过去分词,常搭配的状语有already、yet、so far等。具体用法:(1)表示动作发生在过去的动作对现在造成的影响或者结果,而这种影响或者结果往
5、往是说话人的兴趣所在。常用的状语有already,yet,not yet,now,just,by this time等。例:The bus has come here.公共汽车已经来了。Someone has cleaned the window.有人已经擦了窗户。(2)表示过去已经开始,持续到现在而且可能继续下去的动作。与表示一段时间的状语连用,如today,this week/month/summer,lately,recently,these days,so far,in the past few days,since the end of last year,for a long time等。例:We have lived here for two years.我们在这里住了两年了。翻译练习He has been to Hangzhou several times.他到过杭州几次了。He has gong to Hangzhou,so he cant help us.他去杭州了,所以他不可能帮助我们。He has come to our city.Lets go to visit him.他已经到我们城市来了,我们去拜访他吧。She has been in London for half a year.她在伦敦已经半年了。Thank you