1)若宾语补足语是不带to 的不定式，变为被动语态 时，该不定式前要加"to"。此类动词为感官动词。
feel, hear, help, listen to, look at, make, observe, see, notice, watch
The teacher made me go out of the classroom.
--> I was made to go out of the classroom (by the teacher).
We saw him play football on the playground.
--> He was seen to play football on the playground.
2)情态动词+ be +过去分词，构成被动语态。
Coal can be used to produce electricity for agriculture and industry.
12.1 let 的用法
They let the strange go.---> The strange was let go.
2) 若let 后宾补较长时，let 通常不用被动语态，而用allow或permit 代替。
The nurse let me go to see my classmate in the hospital.
----> I was allowed / permitted to see my classmate in the hospital.
This is a photo of the power station that has been set up in my hometown.
My sister will be taken care of by Grandma.
Such a thing has never been heard of before..
12.3 表示"据说"或"相信" 的词组
believe, consider, declare, expect, feel , report, say, see, suppose, think, understand
It is said that… 据说
It is reported that… 据报道
It is believed that… 大家相信
It is hoped that… 大家希望
It is well known that… 众所周知
It is thought that… 大家认为
It is suggested that… 据建议
It is taken granted that… 被视为当然
It has been decided that… 大家决定
It must be remember that…务必记住的是
It is said that she will leave for Wuhan on Tuesday.
appear, die disappear, end (vi. 结束), fail, happen, last, lie, remain, sit, spread, stand
break out, come true, fall asleep, keep silence, lose heart, take place.
After the fire, very little remained of my house.
比较： rise, fall, happen是不及物动词;raise, seat是及物动词。
(错) The price has been risen.
(对) The price has risen.
(错) The accident was happened last week.
(对) The accident happened last week.
(错) The price has raised.
(对) The price has been raised.
(错) Please seat.
(对) Please be seated.
fit, have, hold, marry, own, wish, cost, notice, watch agree with, arrive at / in, shake hands with, succeed in, suffer from, happen to, take part in, walk into, belong to
This key just fits the lock.
Your story agrees with what had already been heard.
appear, be become, fall, feel, get, grow, keep, look, remain, seem, smell, sound, stay, taste, turn
It sounds good.
die, death, dream, live, life
She dreamed a bad dream last night.
(对) She likes to swim.
(错) To swim is liked by her.
1)wash, clean, cook, iron, look, cut, sell, read, wear, feel, draw, write, sell, drive…
The book sells well. 这本书销路好。
This knife cuts easily. 这刀子很好用。
2)blame, let(出租), remain, keep, rent, build
I was to blame for the accident.
Much work remains.
3) 在need, require, want, worth (形容词), deserve后的动名词必须用主动形式。
The door needs repairing.= The door needs to be repaired.
This room needs cleaning. 这房间应该打扫一下。
This book is worth reading. 这本书值得一读。
4) 特殊结构：make sb. heard / understood (使别人能听见/理解自己)，have sth. done ( 要某人做某事)。
be determined, be pleased, be graduated (from), be finished, be prepared (for), be occupied (in), get marries
He is graduated from a famous university.
注意： 表示同某人结婚，用marry sb. 或get married to sb. 都可。
He married a rich girl.
He got married to a rich girl.
注意：当 need, want, require, worth(形容词)后面接doing也可以表示被动。
Your hair wants cutting. 你的头发该理了。
The floor requires washing. 地板需要冲洗。
The book is worth reading. 这本书值得一读。
The library needs___, but it’ll have to wait until Sunday.
A. cleaning B. be cleaned C. clean D. being cleaned
答案A. need (实意) +n /to do，need (情态)+ do，当为被动语态时，还可need + doing. 本题考最后一种用法，选A。如有to be clean 则也为正确答案。
典：done，"不可能已经"。must not do 不可以(用于一般现在时)。