英语中的被动语态是怎么回事?举几个例句?

英语中的被动语态是怎么回事?举几个例句?

被动语态八注意1．我们知道,主动语态变为被动语态时,通常将主动语态中的宾语变为被动语态的主语；主动语态的主语变为由介词by引导的宾语；谓语动词变为被动语态“be +过去分词”形式,例如：Everyone likes the interesting film.(主动语态) → The interesting film is liked by everyone.(被动语态)They used knives to cut things.(主动语态) → Knives are used to cut things.(被动语态)但是,并非所有由“be +过去分词”构成的形式就是被动语态.有时过去分词已经变为形容词,表示一种状态.试比较：My brother is very interested in English.我哥哥对英语非常感兴趣.（状态）My brother was interested by what I told him.我告诉他的话让我哥哥非常感兴趣.（动态）2．在被动语态中谓语动词一定是及物动词,也就是说必须跟宾语的动词.如：We can make metals into different shapes.(主动语态) → Metals can be made into different shapes.(被动语态)在主动语态中make是及物动词,其动作的承受者即宾语是metals.但是,并非所有的及物动词都有被动语态.比如,表示静态的动词（have、belong to）、宾语是反身代词或相互代词等.例如：He has a nice house.他有一所漂亮的房子.We must help each other.我们应该互相帮助.3．主动语态中的主语在变为被动语态时通常变为由介词by的引出的宾语.如：They have already cut down the trees.→ The trees have already been cut down by them.那些树木已经被他们砍光.如果谓语动词是know,在变为被动语态时,原来的主语变为由to引出的宾语.如：May people know him very well.→ He is well known to many people.很多人都非常了解他.注意：我们之所以用被动语态是因为我们不清楚动作的执行者、或没有必要指出动词的执行者等.因此很多被动语态没有由by引出的宾语.如：People may lose their lives and homes or they may be injured badly in a fire.在大火中人们可能失去性命和家园,要不就是严重烧伤.It is used for protecting the fireman from smoke.它用来保护消防人员以避免吸进烟雾.