英语动词有主动和被动两种语态。主动语态表示主语是动作的执行者,又叫施动者;被动语态表示主语是动作的承受者，又叫受动者。区分主动语态和被动语态，主要看主语是执行者还是承受者。如：
The flowers and grass should be watered .(____语态)
We should water the flowers and grass .(____语态)
◆一 构成
1.被动语态是由助动词be +过去分词构成的，助动词be有时态、人称和数的变化。Tom broke the cup .(主动语态) The cup was broken by Tom .(被动语态)
2.被动语态有以下8种：
一般现在时：be(am / is are) +过去分词 Trees are planted in spring .
一般过去时：be(was / were) +过去分词 The house was built last year .
现在进行时：be(am / is are) + being +过去分词 The car is being repaired .
过去进行时：be(was / were) + being +过去分词
现在完成时：have / has + been +过去分词 The light has been turned off .
过去完成时：had + been +过去分词
一般将来时：will be +过去分词 Lei Feng will be remembered by us forever .
含情态动词的：情态动词+ be +过去分词 My homework can be finished in two hours .
3.被动语态常用于以下场合：
①不知道或没有必要说明动作的执行者是谁时。如：My bike was stolen yesterday .我的自行车昨天被偷了。
②强调动作的执行者时，使用by +动作的执行者。如：The pen was used by my father .这支钢笔是我父亲用过的。
※ 只有及物动词才有被动形式，不及物动词如rise / come / go / take / place / happen等，没有被动形式。
◆二 主动语态变被动语态的步骤
通常遵循以下三个步骤：
1. 把主动语态的宾语变成被动语态的主语。
2. 把主动语态的谓语动词变为与其时态相对应的被动形式，且与被动语态的主语保持人称和数的一致。
3. 将主动语态的主语变为介词by的宾语，置于句末。by +宾语在句中常省略。
主动语态：Many people speak English . 这里还需要连线!
被动语态：English . is spoken by many people .
如：Lu Xun wrote this book . This book was written by Lu Xun .这本书是鲁迅写的。
People are cutting down many trees now . Many trees are being cut down now .现在许多树正被砍伐。