2010年同等学力申硕英语语法辅导（第1讲）动词不定式（一）
不定式由“to+动词原形”构成，其否定形式是“not to do”。不定式可以带宾语状语构成不定式短语，没有人称和数的变化，但有时态和语态的变化。不定式可作主语、宾语、状语、表语和定语，但不能单独作谓语。不定式的逻辑主语可用“for+名词或代词宾格”构成。1. To see is to believe.（主语）
2. It is right to give up smoking.（主语）
3. He wanted to go.（宾语）4. I find it interesting to work with him.（宾语）
5. I have some books for you to read.（定语）
6. I came here to see you.（状语）
7. The question is difficult to answer.（状语）8. He is too old to do that. （状语）
9. The room is big enough to hold us.（状语）
10. To tell the truth, I don’t agree with you. （独立结构）11. He gave the order to start the attack.（同位语）
在feel, hear, listen to, look at, notice, observe, see, watch, have, let, make 等词后的补足语中，不定式不带to。但是这些句子如果变成被动结构时，就必须带to。1. I often hear him sing the song.
He is often heard to sing the song.
2. They made the boy go to bed early.
The boy was made to go to bed early. 不定式动词在介词but, except, besides后面时，如果这些介词之前有行为动词do的各种形式，那么，这些介词后的不定式不带to，否则要带to。1. She could do nothing but cry.
2. What do you like to do besides swim?
3. I have no choice but to go.
4. They desired nothing but to succeed. 在cannot but, cannot choose but 与cannot help but 之后的不定式一般不带to. 1. I cannot but admire his courage. 2. He could not choose but love her.
3. The cause could not help but be advanced today.
在would rather, would sooner, other than would rather…than 等之后用不带to的不定式。
1. I would rather go than stay.
2. No one could do other than admire it. 3. They would sooner go for a drink.
动词不定式作定语时，如果其与所修饰的名词或代词呈动宾关系时，即通常所谓的反射不定式，此时不定式的动词是不及物动词，或者所修饰的名词或代词是不定式动作的地点、工具等，不定式后面须有相应的介词。
1. There is nothing to worry about.
2. He is looking for a room to live in.
3. Please give me a knife to cut with.
4. I need a pen to write with.
但是，不定式所修饰的名词如果是time, place或way, 不定式后面的介词习惯上要省去。
He had no money and no place to live.
动词不定式与疑问词who, which, when, where, how, what等连用，有句中起名词作用，可充当主语、表语、宾语等。
1. He didn’t know what to say.2. How to solve the problem is very important.
3. My question is when to start.
4. I can tell you where to get this book.
有时疑问词前可用介词。e.g. I have no idea of how to do it.
动词不定式在与why 连用时，只用于why 或why not开头的简短疑问句中，后面跟不带 to 的动词不定式。
1. Why talk so much about it?
2. Why not have a rest? 为了避免重复句子前面已经出现过的动词，不定式常可省去动词原形，只留下不定式符号to。
1. He may go if he wishes to. 2. Don’t go till I tell you to.
2010年同等学力申硕英语语法辅导（第2讲）动词不定式二
九、不定式的逻辑主语：for+名词（代词）+不定式
1. It’s just impossible for a child to do that job.2. It is necessary for goods to be packed in strong cases.
当表语形容词为good, kind, nice, honest, wise, clever, right, thoughtful, tactful（老练的）, polite, courteous（礼貌的）, sensible, bold, bad, stupid, cruel（残忍的）, rude, impolite, wrong, silly等可以修饰人的行为、性格特征等词语时，不定式的逻辑主语由“of+名词（代词）+不定式”构成。
1. It is wise of him to settle the case that way.
2. It’s kind of you to say so.
十、动词不定式的时态
不定式的一般形式所表示的动作，通常与谓语的动作（状态）同时（或几乎同时）发生，或是在它之后发生。
e.g. I saw him go out.
如果谓语表示的动作（情况）发生时，不定式表示的动作正在进行，这时不定式就要用进行式。
e.g. 1. I am very glad to be working with you.
2. You won’t want to be washing at this time of night.
如果不定式的动作发生在谓语动词之前，就要用完成式。
e.g. 1. I’m sorry to have kept you waiting.
2. To have known her is a privilege. 十一、动词不定式的被动式
e.g. 1. He asked to be sent to work in the countryside.
2. It is possible for our hopes to be realized. 3. The problem remains to be solved. 在want, like, wish, have, get, leave, see, watch, hear, make等动词后用作宾语补语的被动不定式可省去to be.
e.g. 1. When visiting a foreign country, I sometimes found it difficult to make myself understood.
2. You will see this product advertised wherever you go.
不定式修饰的名词或代词和不定式逻辑上构成主谓关系时，不定式用主动形式。e.g. Have you got a key to unlock the door(A key unlocks the door.)
不定式和它前面被修饰的名词或代词构成逻辑上的动宾关系，又和该句主语构成逻辑上的主谓关系时，不定式常用主动形式。e.g. 1. I have got a letter to write. (I write letter)
2. He needs a room to live in. (He lives in a room.)
3. I know what to do. (I do what.) 这句话改成从句要用被动形式：I know what is to be done.
不定式作表语形容词的状语，和句中主语构成逻辑上的动宾关系时，不定式多用主动形式。
e.g. 1. He is hard to talk to. (to talk to him)
2. The book is difficult to understand.
(to understand the book) 在there be 的结构中，当说话人考虑的是必须有人去完成某件事时，不定式用主动形式，如果说话人强调的是事情本身必须完成，则用被动形式。
e.g. 1. There is a lot of work to do.
(Somebody has to do the work.)
2. There is a lot of work to be done.
(The work has to be done.) 3. There is nothing to do. 意为无事可做，感到十分乏味。
4. There is nothing to be done. 意为某东西坏了，无法使之恢复正常。
有些句子习惯上须用不定式被动式。e.g. 1. Such things are to be seen any day.
这种事哪一天都可遇到。
2. This is a day never to be forgotten.
这是令人难忘的一天。