不定式的时态和语态
主动语态
一般式 to write
进行式 to be writing
完成式 to have written
被动语态
一般式 to be written
进行式 －
完成式 to have been written
不定式被动态的句法功能
做主语
To be obeyed is natural to her.
她生性要别人听命于她.
做外置主语
外置主语又称真实主语
It’s great honor to be invited to the banquet.
承蒙受邀赴宴,倍感荣幸.
做宾语
This room needs to be cleaned at once.
这房间需要立刻打扫.
做表语
A lot of work remains to be done in the office.
许多工作留到办公室去做.
做定语
The large building to be built here is a library.
将在这儿建一座图书馆.
做状语
She felt angry to be left alone.（原因状语）
被单独留下,她感到气愤.
做主补
The book intended to be read and not to be torn.
书是供人阅读而不是让人撕毁的.
做宾补
The commander ordered the bridge to be burnt.
指挥员命令把桥烧掉.
不定式的句法功能
一、不定式作主语
To learn a foreign language is not easy.
学外语不容易.
Is it necessary to complete the design before National Day?
有必要在国庆节之前完成这个设计吗?
二、不定式作宾语
I forgot to turn the oven on.
我忘记打开炉子.
三、不定式作宾补
Will you help me plant this tree,please?
请您帮我种这棵树好吗?
四、不定式作定语
He has a lot of questions to ask.
他有许多问题要问.
五、不定式作表语
Disney’s greatest wish was to be a famous artist.
迪斯尼最大的愿望就是成为一个著名的艺术家.
六、不定式作状语
She searched the top of the hill and stopped to rest on a big
rock by the side of the path.
她搜查了山顶上,然后在路边的一块大石头上停下来休息.
不定式作主语（1）
不定式作主语有以下三种句型：
句型（1） 不定式短语 + 谓语动词
句型（2） It's + 形容词 + for/of 逻辑主语 + 不定式短语
句型（3） It's + 名词 + for 逻辑主语 + 不定式短语
在这一条目中,只讲述句型（1）,例外两个结构在以下条目中讲述.
To know oneself is difficult.
了解自己很困难.
在英语句子的表述中倾向主语短小一些,谓语部分长一些,以保持句子的结构平衡.故上句可以改写如下：
It's difficult to know oneself.
To go to school on foot every day takes me half an hour.
It takes me half an hour to go to school on foot every day.
我每天步行上学花费半个小时.
To read this book through will require time and patience.
It will require time and patience to read this book through.
读完这本书需要时间与耐心.
不定式作定语（1）
不定式短语作定语时,必须放在名词中心词的后面,作后置定语
Do you have anything more to say?
你还有什么话要说吗?
It's time to start spring sewing.
春播的时间到了.
That's the best way to solve the problem.
这是解决这个问题的最好办法.
You have no right to talk like that.
你没有权利那样说话.
Perhaps in years to come we shall meet again.
或许在未来的岁月中我们还会见面.
如果不定式短语作前置定语,则要采用“带连字符的复合词”
定式作表语
作表语的不定式短语通常是说明主语的内容,这时主语通常是如下名词：
hope,idea,job,plan,wish,aim,purpose,thing,business
The purpose of new technologies is to make life easier,not to make it more difficult.
新技术的目的是使生活更便利,而不是更繁琐.
Her wish is to become a singer.
她的愿望是当一名歌手.
Our plan is to finish the work in two weeks.
我们的计划就是在两星期内完成这项工作.
