被动语态的常见句型
1.主语（受动者） ＋ be ＋ 过去分词 ＋ （by ＋ 施动者）.例如：
He was scolded by his parents.
2.主语 ＋ get ＋ 过去分词 ＋ 其它成分.例如：
The boy got drowned last summer.
She got fired because of her faults.
注意 使用这种结构时一般不能带有“by ＋ 施动者”
3.情态动词 ＋ be ＋ 过去分词.例如：
This problem must be worked out in half an hour.
The baby should be taken good care of by the baby?鄄sitter.
4.带有双宾语（直接宾语和间接宾语）的主动句变为被动句,其主语可以是直接宾语,也可以是间接宾语.例如：
She lent me a bike.
被动：1） I was lent a bike (by her).
2） A bike was lent to me (by her).
5.当“动词 + 宾语 + 宾语补足语”结构变为被动语态时,将宾语变为被动结构中的主语,其余部分不动.例如：
Someone caught the boy smoking a cigarette.
被动：The boy was caught smoking a cigarette.
6.在使役动词have,make,get以及感官动词see,watch,notice,hear,feel,observe等后面加不定式作宾语补语时,在主动结构中不定式to要省略,但变为被动结构时,要加to.例如：
Someone saw a stranger walk into the building.
被动：A stranger was seen to walk into the building.
7.如果宾语是that 从句,变为被动结构时一般用it作被动句的形式主语.例如：
They know that he is an expert.
被动：It is known that he is an expert./ He is known to be an expert.