被动语态的几个特殊情况
一、带有双宾语的主动句在变为被动语态时，可将其中任何一个宾语变为主语，而另一个仍跟在动词后保持不变。若把直接宾语改为被动语态的主语，间接宾语前必须用介词 to(有的用 for).
 
例如： Those children gave the teacher some flowers.
 
The teacher was given some flowers by those children.
 
/Some flowers were given to the teacher by those children.
 
二、含有复合宾语的主动句在变为被动语态时，只能将宾语改为被动语态的主语，而宾语补足语不可变为主语。
 
例如： My friends made me chairman.
 
I was made chairman by my friends.
 
三、含有let, make, see, hear, watch, find, feel等动词后接省去to的不定式作宾语补足语的主动句，在变为被动语态时一定要把to加上。
 
例如： Someone often hears your sister sing in the room.
 
Your sister is often heard to sing by someone in the room.
 
四、祈使句变为被动语态时，应把原句改为“Let+原句的宾语＋be +v. – ed ”形式。
 
例如： Open that window.
 
Let that window be opened.
 
五、疑问词作主语的主动句变为被动语态时，应该把“by+疑问词（宾格）”放在句首。
 
例如： Who gave a talk last week?
 
By whom was a talk given last week?
 
六，含有否定词 none, no one, nobody, nothing等作主语的主动句在变为被动语态时，谓语动词应改为否定形式，且原句的主语也必须改用其他的词来作介词by的宾语。
 
例如： Nobody has seen this TV play in their class.
 
This TV play hasn't been seen by anybody in their class.