不定式被动态的用法
一、 不定式与其逻辑主语之间是被动关系时（其逻辑主语是不定式动作的承受者）,要用不定式的被动式。
二、 动词不定式的被动语态有两种形式：
1）一般式 （not/never ）to be done （其动作与谓语动词的动作同时发生或在其后发生）
2）完成式 （not/ never） to have been done （表示不定式动作发生在谓语动词之前）
e.g. He ordered the bridge to be built within the month.他命令在月内建成这座桥。(一般被动式)
She was glad to have been given so much help.得到如此多的帮助, 她很高兴。(完成被动式)
✧ 通常在believe, suppo, say, report等动词构成的句子中可以进行主动语态到被动语态以及被动语态和动词不定式的转换。如：
They say that Mike is sick in bed. — It is said that Mike is sick in bed.
—Mike is said to be sick in bed.
根据上面的例子仿写下面的句子：
People believe that he was killed.
—_______________________________________
—________________________________________
三、 不定式的被动形式有下列用法:
✧ 作主语（常用it做形式主语）
It is an honor for me to be asked to speak here.
✧ 作宾语(动词+ to be done/to have been done)
She asked to be nt to work in Xinjiang.
✧ 构成复合宾语(宾语补足语)：有些及物动词接了宾语之后需要接宾语补足语补充说明宾语的有关情况，否则句子意思不完整。--------主语+及物动词+宾语+爱与孤独宾补（复合宾语）
He wanted the letter to be typed at once.
✧ 构成复合谓语：某些动词+to be done/to have been done。这些动词包括：表示说话及心理状态的动词有：say, report, believe, suppo, think, know, consider+ to be done/to have been done
✧ 作定语(放在名词或代词之后)：中心词是不定式的承受者。不定式的动词应该是及物动词（及物动词时不带宾语）或者相当于及物动词的短语（不及物动词+介词/副词）；作定语通常修饰the first/the last/the third等。
This is the last question to be discusd.
✧ 作状语：
She was too young to be assigned such work.
总结：不定式有时还可以有完成式的被动式, 在句中作主语、宾语、定语, 或者构成复合宾语、复合谓语等。请判断下列句子中不定式的被动态作什么成分。
It is a good thing for him to have been criticized. （ 飘飘欲仙灰太狼）
She preferred to have been given heavier work to do. （ ）
He thought it an honor to have been invited to the party. （ ）
The book is said to have been translated into many languages. （ ）
She was the first woman to have been elected to such a post. （ ）
三、 不定式的主动形式表示被动意义
1. 在there be结构中(There ＋be ＋n. ＋to do)。。用主动式作定语, 重点在人, 用被动式作定语, 重点在物 .例如：
There is a lot of homework to do/to be done. There is no time to lo (to be lost).
工程延期申请报告
2. 在“n+ be + adj + to do”结构中。常用的形容词有easy, difficult, hard, impossible, nice, pleasant, light, heavy, fit, interesting，important, expensive, cheap, dangerous等。
如：He is hard to convince. He is an impossible person to work with．
2. 在“too…to do; enough…to…”结构中。(n. ＋be＋too＋adj. ＋to do /n. ＋be ＋adj. ＋enough to do)如：
The passage is too hard to translate.
The problem is too difficult (for us) to work out/(to be worked out)．
The hou is big enough (for us) to live in./to be lived in.
4. 在“with+n+to do”结构中。不定式表示的动作将要发生，且句子的主语是该动作的逻辑主语。例如：
With nothing to do, he lay in bed． With so many exercis to do, I can't go to the cinema．
关于包拯的故事5. 当不定式隐含在for sb to do结构中时。例如：
This is the best book to read (=for us／you to read)．
The important thing to do is to lock the door when we leave the hou．
6. rent ,blame let 等动词常用不定式的主动形式表示被动含义
The hou is to let． I felt l was to blame.
7.不定式做定语，和所修饰的名词之间构成动宾关系，又和逻辑主语构成主谓关系时， 不定式要用主动形式表示被动含义。 have（give, show）挂钩图片大全sth. to do
I have a lot of things to do我是特种兵之子弹上膛 this afternoon. He has a lot of homework to do.
I have a letter to type today, so I can’t go shopping with you. (I是to type的逻辑主语)
I have a letter to be posted, can you help me?
Do you have any clothes to wash? Do you have any clothes to be washed?
主谓关系：主语发出谓语这个动作。
动宾关系：谓语所表示的动作被宾语所承受。
8．在疑问词what/which/whom+移动电视盒子不定式结构中，主动表被动
eg. I don’t know which to choo. He asked me what to do.
9. 在need , require, want , worth (adj )后的动名词可以主动表被动 ,相当于动词不定式的被动形式。(worth的动名词形式相当于试验检测worthy to be done)
eg . The door needs repairing/to be repaired. This book is worth reading/worthy to be read.
Her mother is ill .She needs looking after/to be looked after.
✓ 动词不定式主动语态形式的使用要比被动语态形式的使用普遍, 有时(尤其在口语中)
虽然意思上是被动的, 也往往用主动语态形式来表示。
I have three motors to repair today. The task is difficult to finish on time.
Practice：
1. Having a trip abroad is certainly good for the old couples but it remains ______ whether they will enjoy it. (MET2001)
A. to e B. to be en C. eing D. en
2. Charles Babbage is generally considered _____the first computer. (MET1993)
A. to invent B. inventing C. to have invented D. having invented
3. There are five pairs _____, but I'm at a loss which to buy. (1999上海高考)
A. to be chon B. to choo from C. to choo D. for choosing
4. With a lot of difficult problems ____, the newly-elected president is having a hard time.
