英语动词有两种语态，主动语态和被动语态。主动语态表示主语是动作的实行者，被动语态表示主语是动作的承受者。如：
They will build a new bridge over the river. A new bridge will be built over the river.
助动词be + 及物动词的过去分词构成。
一般地讲，被动语态可用于英语的各种时态。为了能准确地运用被动语态，重点是要学会be动词的各种时态变化。各种时态的被动语态举比如下：
1、一般目前时的被动语态am / is / are + 动词的过去分词Our classroom is cleaned every day.This car is made in China.
2、一般过去式的被动语态was / were + 动词的过去分词His desk was cleaned just now.The station was built in 1928.
3、目前进行时的被动语态am / is / are + being + 动词的过去分词A new factory is being built in our city now.Some trees are being cut down in the park.
4、过去进行时的被动语态was / were + being + 动词的过去分词A new factory was being built in our city at that time.Some babies were being looked after by Miss Chen last year.
5、一般以后时的被动语态: will / shall + be + 动词的过去分词 am / is/ are + going to be +动词的过去分词.Some new factories will be built in our city this year.Your watch is going to be mended in an hour.
6、过去以后时的被动语态:.would / should + be + 动词的过去分词.was / were +going to be + 动词的过去分词.She said that some new factories would be built soon in our city.He thought that your watch was going to be mended after an hour.
7、目前完成时的被动语态have / has + been + 动词的过去分词Some new factories have been built in the city since last year.Your watch has been mended already.
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。You must hand in your compositions（作文） after class.Your compositions must be handed in after class.
不及物动词没被动语态，如：rise, happen, succeed, remain, lie等。一些不及物动词短语也没被动语如：take place, break out, belong to, lose heart, consist of, add up to等。The fire broke out in the capital building.误：The fire was broke out in the capital building.感官动词作系动词用，无被动语态。The cake smells nice.
1、三步骤1．把主动语态的宾语变成被动语态的主语。2．把主动语态的谓语变成被动语态的“be＋过去分词”结构；时态要与原句维持一致。3．将主动语态的主语改为介词by之后的宾语，放在谓语动词之后（有时可省略）。假如原句主语是地址名词，在被动语态中用in + 地址名词作状语。
2、含直接宾语和间接宾语的主动语态改为被动语态时有两种状况：1. 把间接宾语改为被动语态的主语，直接宾语仍保留原位；He gave the boy anapple．→The boy was givenan apple．2. 把直接宾语改为主动语态的主语，此时，间接宾语前要加介词to或 for。He gave the boy anapple．→An apple wasgiven to the boy．Her father bought hera present．→ A present wasbought for her by her father.的动词改为被动语态时，一般把主动结构中的宾语改为主语，而宾语补足语保留在谓语动词后面。We call him Xiao Wang．→He is called XiaoWang．He cut his hair short．→His hair was cutshort．They told him to helpme．
4、在see, watch, hear, notice, listen to, look at, make, feel等动词后作宾语补足语的动词不定式都不带 to，但改成被动语态后都带to。We often hear him play the guitar.→He is often heard to play the guitar.They watched thechildren sing that morning．
→The children werewatched to sing that morning.
