动词不定式的用法
不定式结构作主语
1、不定式前置
1） Derive [A] mineral resources from [B] sedimentary rock [C] is a [D] major modern industrial activity.
2） in the matriculation for postgraduate in a short time is realy a hard nut.
[A] To make high scores[B] To make low goal[C] To the high scores[D] Make the low goals
2、上述形式一般情况不多见，作为考试的规范英语，如果不定式较长，显得头重脚轻,则可由代词“it”作形式主语（形式主语“it”不能由“that”或“this”等其他代词代替），而将不定式放到后面
It is really a hard nut to get high scores in the matriculation for postgraduate in a short time.
3） John admitted that it\'s always difficult.
[A] for him being on time[B] being on time for him
[C] for him to be on time[D] on time for him
4） It is difficult for me [A] to be concentrating [B] while someone [C] is using [D] a vacuum cleaner.
3、不定式后置的情况不仅限于动词是系动词，也适用于其他动词
It took us a great deal of efforts to finish that task.
It made him extremely happy to get contact with his family in Taiwan since they separated more than 40 years ago.
4、不定式结构所表示的动作是谁做的，即不定式的逻辑主语，通常可以在特定的上下文中能看出，也可以通过带“for +名词短语”辨出
It is quite important for us to read good books during the period of general review。
It is not difficult for those who study maths well to pass the exam.
5、在某些形容词（如careless,clever,considerate,foolish,good,impolite,kind,naughty,nice,silly,stupid等）作表语时，不定式后可以加of来引导出其逻辑主语
It is very kind of you to help me./It is stupid of him to do such a silly thing.
间或也可用for + there to be 表示（而且there后面的不定式只能是to be）。
It\'s a great pity for there to be much trouble in the company
不定式作宾语
不定式作宾语有两种：一种是及物动词后直接跟带to的不定式；另一种是“动词+疑问词+带to的不定式”
1、动词+带to的不定式结构
只能跟动词不定式的动词,常见的有：afford, agree, aim, appear, arrange, ask, believe, care, claim, decide, decline（拒绝）, demand, desire, determine, endeavor, expect, fail, hesitate, hope, intend, learn, long, manage, mean（想要）, offer（表示愿意做…）, pretend, promise, refuse, seek（试图）, swear, undertake, wish（想要）等。
5） We refuse that there are insufficient funds in the great vaults（银行保管库） of this nation.
[A] to believe [B] to be belived[C] beliving
[D] have belived
6） The green turtle has been known over 2,000 miles to return to a nesting site.
[A] in the navigating [B] the navigation [C] to navigate [D] navigation
7） For the [A] first time Venusian scientists managed landing [B] a satellite on the planet Earth, and it has been sending [C] back signals as well as [D] photographs ever since.
8） The day is past when Chinese universities and colleges to give high school diplomas to all who sit through four years of instruction, regardless of whether any visible results can be discerned.
[A] afforded[B] affording[C] to afford
[D] can afford从上例我们可以看出afford一般与can和can\'t或could和couldn\'t连用
动词+疑问代（副）词+不定式这类动词
常见的有：advise,decide, discuss, find out, forget, inquire, know, learn, regard, remember, see, settle, teach, tell, think（=consider）, understand, wonder等。这些疑问代（副）词有what, when, where, which, how, whether等,但不包括why,如：
He does not know how to go there
when to speak before strangers.
who（m） to visit.
which one to choose.
You can decide whether to go forward or stay here.
when to see a doctor.
I will show you what to do.
where to go.
how to deal with it.
其中,1）和2）中不定式的逻辑主语仍是句子的主语,分别为He和You；而3）中不定式的逻辑主语则不是句子的主语I,而是宾语you.
9） The director of this organization must know .
[A] to manage money, sell his product and beable to satisfy stockholders
[B] managing money, selling, and be able to satisfy the stockholders
[C] how to manage money, sell his product, and satisfy the stockholders
[D] money management, selling and being able to satisfy the stockholders
10） To tell you the truth, I really don\'t know how deal with a man like him.
[A] can I[B] well[C] to[D] much
3、有时，不定式跟作主语时一样，可由it来代替，而把不定式放到后面去He makes it a rule to take a walk before breakfast.
I think it interesting to play football while it is snowing hard.
We find it difficult to get everything ready before the time you require.
She cosiders it important to make friends with them.
I don\'t think it necessary to argue with them on this problem.
4、有时THERE和TO BE连用表示“有”或“存在（某情况）”等
It is impossible for there to be any more.
Would you like there to be a meeting to discuss the problem？
I expect there to be no argument about this？
有时在个别的介词后可用“疑问词+不定式结构”作其宾语
He has his own decision of how to do it.
