武哥4——不定式
什么是不定式？
动词不定式是动词的一种非限定形式（不受时间变化约束），由“to+动词原形”构成，在句子中起名词、形容词或副词的作用，同时也保留动词的一些特征，可以带宾语或状语，等等
A man is a good thing to come home for, but even better to come home with.（《绯闻女孩》第二季第一集）在家等着的男人是好的，不过一起回家的男人更好。
作主语：
To love others is to be loved.= if you love others, you will be loved by others.爱人即爱己。
It would be wrong for people to marry for money.（it +be+adj+for sb+to do）
It was annoying of Jim to lose my bike. (it+be+sdj+of sb+to do)
It's a shame to say like that. (it+be+n+to do)
It's against my principles to do such a thing. (it+be+prep+to do)
作表语
The purpose of the exchange program is to promote the understanding between the two countries. 这项交流计划旨在促进两国之间的相互了解。(主语=表语，可以互换)
You must speak out, if we are to remain friends.如果我们还想继续做朋友的话，你就必须痛痛快快的把话说出来。
What am i to say if they ask me the question? 要是他们问我这个问题，我该怎么回答呢？
The regulations are to be observed. (=must be observed，相当于情态动词)
Children are not to smoke.（表示禁止、命令）
不定式做表语，主动表被动
She is to blame 她应该受到责备 The house is to let. 该房屋出租
A great deal is yet to do. 还有很多事要做 The result is not long to see. 结果不久会看到
Something is still to find out. 有些东西还有待查明 Little remains to do. 没有什么可做的了
主语是all, what等词引导的从句，做表语的不定式一般不用to
如果主语是all,what引导的从句，主语受only, first, one, least或形容词最高级修饰，且后面的从句或短语中有实义动词do时，做表语的不定式前不用to
The least you can do is help up a little.
What she did to the matter was keep silent.
The only thing i could do was go it alone.
All he does is gossip about others.
作宾语
1. feel, find, judge, make, think, believe, consider等动词后如果是不定式作宾语，补语是形容词（或名词），常用it作形式宾语，不定式后移。
I find it difficult to work with him.
He thought it a great pity not to have invited her.
2. agree + to do(事情未发生)
enjoy/resist+ doing (事情已发生)
作宾补
1. hope, demand, suggest等动词后，不能接to do作宾补
He hoped his sister to lend him a hand（错误）
He hoped that his sister would lend him a hand. √
I suggested him not to go there alone. （错误）
I suggest that he not go there alone. √
2. 以下动词后可以接“疑问词+to do”作宾语，疑问词+不定式还可以作主语、主补、介宾、或定语等。
decide, discover, explain, consider, ask; find out, forget, know, imagine, learn;
observe, remember, tell, show, think; understand, wonder等
I wonder who to invite.
3. 在hear, listen to, feel. see, look at, watch, notice, observe, perceive, let make, bid, have, not, leave(let)等动词后，不定式作补语省略to，被动形式还原to
He made her give up the property.
作定语
1. 动词不定式与其所修饰词之间往往有动宾关系，如果该不定式是不及物动词，或该不定式本身有宾语，其后应有必要地介词。
He is a pleasant fellow to work with.他是个很好共事的人
2. 作定语的不定式有时含有情态意义，相当于may, can, must, will, would或should所具有的含义。
He has no friend to depend on. 他没有可以依靠的朋友。
3. 不定式可以修饰there be 结构中作主语的名词
There is nothing to worry about.没什么可担心的
4. 不定式常用于“have the+抽象名词” 结构中
He has the goodness to do it. 他好意做那件事
5. 有些动词和形容词后长跟不定式，这些动词和形容词派生出来的名词后也可用不定式作定语。
ability, agreement, anxiety, attempt, claim decision, determination, need, plan, promise
readiness, tendency, willingness, wish, impatience obligation, inclination, eagerness....
She fulfilled her promise to send him abroad. 他履行了送他出国的诺言。
He made an attempt to overcome his weaknesses. 他努力克服自己的弱点。
6. the first, the second, the last, the best, the only thing等长跟不定式作定语。
He is always the first to answer questions, 他总是第一个回答问题。
作状语
To save the child, he laid down his life. (目的)
Opening the window, she saw a bird flying over.（时间状语）
To open the window, she saw a bird flying over.（错误❌）
1. 表结果
A few days later he came back only to find that the troops had left. （结果）
下列形容词是对人进行表扬或批评的，后面常接不定式表结果
right, polite, crazy, generous, good greedy, kind, selfish, silly, splendid, nice
He is generous to lend us a large sum of money.
2. 不定式作原因状语时，一般放在句尾。不定式常跟在一些形容词或过去分词后，说明产生这种情绪的原因。
He felt shame for his daughter to have told lies （先于谓语动词发生）
He was happy to have been staying with his uncle.（先于谓语动词发生）
注意不定式状态变化：
3. 表明说话人态度，在句中作独立成分
to tell you truth, truth to say to be plain to put it straight
to bring the story short to cut the matter short to return to my subject
to change the subject to use his own words to give him his due公正地说
strange to say curious to mention to be brief简言之
to be exact to be frank with you to say nothing of姑且不讲
to conclude to crown all to put it plainly
to start with=to begin with to sum up
表示更不用说： to say nothing of；not to say ； not to mention ；not to speak of ；let alone
4. 表示条件：
One will get into trouble to do such a thing.
5. 省略to的不定式
had better, had best, would rather, would rather...than.., rather than
would sooner, would sooner... than..., cannot but, cannot help but, do nothing but
might(just) as well, do nothing besides, do nothing than(except, save)等
She can't do anything but ask silly question
