2011年大学英语六级非谓语动词语法精要

　　完成式: 不定式的一般形式所表示的动作, 通常与主要谓语表示的动作(状态)同时(或几乎同时)发生, 或是在它之后发生. 假如不定式所表示的动作, 在谓语所表示的动作(状态)之前发生, 就要用不定式的完成式.
　　I am glad to have seen your mother (= I am glad I have seen your mother).
　　(比较: I am glad to see you.)
　　He is said to have written a new book about workers.
　　He pretended not to have seen me.
　　进行式: 如果主要谓语表示的动作(状态)发生时, 不定式表示的动作正在进行, 这时要用不定式的进行式.
　　You are not supposed to be working. You haven’t quite recovered yet.
　　We didn’t expect you to be waiting for us here.
　　He pretended to be listening attentively.
　　完成进行式: 在谓语所表示的时间之前一直进行的动作, 就要用不定式的完成进行式.
　　The struggle was known to have been going for twenty years.
　　We are happy to have been working with you.
　　被动式: 当不定式的逻辑上的主语是不定式所表示的动作的承受者时, 不定式一般要用被动形式.
　　It is an honour for me to be asked to speak here.
　　She hated to be flattered.
　　He wanted the letter to be typed at once.
　　This is bound to be found out.
　　There are a lot of things to be done.
　　She was too young to be assigned such work.
　　功用: 不定式可以作主语 (a), 宾语 (b), 表语 (c), 定语 (d) 或是状语 (e).
　　a. To scold her would not be just.
　　b. We are planning to build a reservoir here.
　　c. One of our main tasks now is to mechanize agriculture.
　　d. Do you have anything to declare?
　　e. We have come to learn from you.
　　不带to 的不定式:
　　在“动词+ 宾语+不定式”结构中, 如果动词是表示感觉意义的see, hear, watch, smell, feel, notice等, 或是表示“致使”意义的 have, make, let等, 其后的不定式结构不带to.
　　John made her tell him everything.
　　这类结构转换为被动语态时, 后面的不带to 的不定式一般还原为带to 的不定式.
　　She was made to tell him everything.
　　在 had better, had best, would rather, would sooner, would just as soon, might (just) as well, cannot but 等搭配之后, 动词不定式也不带to.
　　I’d rather not have eggs and bacon for breakfast.
　　They cannot but accept his term.
　　在make do, make believe, let drop, let fall, let fly, let slip, let drive, let go of, let there be, hear say, hear tell, leave go of等固定搭配中, 用不带to的动词不定式.
　　John let fly a torrent of abuse at me.
　　I’ve heard tell of him.
　　在动词help(或help +宾语)之后可用不带to的不定式, 也可用带to的不定式.
　　Can I help (to) lift this heavy box?
　　在介词except, but 之后, 如果其前有动词do的某种形式, 不定式一般不带to, 反之带to.
　　There is nothing to do except wait till it stops raining.
　　Smith will do anything but work on a farm.
　　There’s no choice but to wait till it stops raining.
　　连词 rather than, sooner than 置于句首时, 其后的不定式不带to.
　　Rather than push the book back as he wanted to do, he forced himself to pick it up.
　　出现在句中其他位置时, 其后的不定式有时带to, 有时不带to.
　　He decided to write rather than telephone.
　　The manager believes it is important to invest in new machinery rather than to increase wages.
　　用作补语的动词不定式, 如果主语是由“all + 关系分句”，“thing +关系分句”，“what分句”或“thing +不定式结构”等构成，并带有do的某种形式，这时，作为主语补语的不定式可以省to，也可以不省.
　　What he will do is (to) spoil the whole thing.
　　All you do now is complete the form
　　The only thing I can do now is go on by myself.
　　The thing to do now is clear up this mess.
　　The least I can do is drive everybody else closer to the issue.
　　不定式的其他用法
　　too…to 结构通常表示否定意义:
　　She was too young to understand all that.
　　enough…to结构则表示肯定意义:
　　She was not old enough to understand all that.
　　not too, but too, all too, only too等和不定式连用时,不定式一般不表示否定意义:
　　He’s only too pleased to help her.
　　so…as (to)这种结构也可用不定式作状语:
　　Be so kind as to drop in some time when you are free.
　　如果要说明不定是表示的动作是谁做的, 可以在不定式前加一个for引起的短语:
　　It is not hard for one to do a bit of good.
　　It is a great honour for us to be present at this rally.
　　在以某些形容词(如 kind, good, nice, wise, unwise, clever, silly, wrong, right, foolish, stupid, careless, considerate, rude, naughty, impolite等)作表语时, 不定式前可加一个of引起的短语, 来说明不定式指的是谁的情况:
　　It’s kind of you to think so much of us.
　　(It is) Awfully good of you to come and meet us.
　　It’s very nice of you to be so considerate.
　　It’s unwise of them to turn down the proposal.
　　V+ing形式(现在分词及动名词)
　　形式
　　完成式: 如果要表示动名词代表的动作在谓语所表示的动作之前发生, 通常用动名词的完成形式.
　　He didn’t mention having met me.
　　I regret not having taken her advice.
　　在某些动词后(或成语中), 常用(或可以用)动名词的一般形式, 尽管动作是在谓语所表示的动作之前发生的.
　　Excuse me for coming late.
　　I don’t remember ever seeing him anywhere.
　　现在分词的完成式主要用在状语中, 表示这动作在谓语所表示的动作之前发生.
　　Having been there many times, he offered to be our guide.
　　Having found the cause, they were able to propose a remedy.
　　另外, 独立结构也可用现在分词的完成形式.
　　The guests having left, they resumed their discussion.
　　The children, having eating their fill, were allowed to leave the table.
　　被动式: 当一个动名词逻辑上的主语所表示的是这动作的对象时, 动名词一般要用被动形式.
　　His being neglected by the host added to his uneasiness.
　　He couldn’t bear being made fun of like that.
　　但要注意, 在want, need, deserve, require 等动词后, 尽管表示的是被动的意思, 却用动名词的主动形式.
　　My pen needs filling.
　　The point deserves mentioning.
　　This problem requires studying with great care.
　　在worth这个形容词后情形也是这样.
　　Her method is worth trying.
　　现在分词的被动式可以用来作定语, 宾语补足语, 状语及用于独立结构中.
　　This is one of the experiments being carried on in our laboratory.
　　You’ll find the topic being discussed everywhere.
　　Being asked to give a performance, she couldn’t very well refuse.
　　These are sold at reduced prices, the defects always being pointed out to the customers.
　　完成被动式: 如果表示的动作在谓语表示的动作之前发生, 有时需要用动名词的完成被动式.
　　I don’t remember having ever been given a chance to try this method.
　　但在多数情况下都避免使用这一形式, 而用一般被动形式代替, 以免句子显得累赘.
　　现在分词的完成被动式一般用来作状语或用于独立结构中.
　　Having been given such a good chance, how could she let it slip away?
　　The decision having been made, the next problem was how to make a good plan.
　　All the compositions having been written and collected, the teacher sent the students home.
　　句法功用
　　作主语:
　　Walking is good exercise.
　　It’s nice talking to you.
　　There is no denying the fact that the new method has greatly raised labour productivity.
　　作宾语:
　　Your shoes need polishing.
　　You mustn’t delay sending the tractors over.
　　He avoided giving us a definite answer.
　　作介词宾语: 动名词作介词宾语用的时候最多. 它常可以用在某些成语后面, 常见的有: insist on, persist in, think of, dream of, object to, suspect…of, accuse…of, charge…with, hear of, approve of, prevent…from, keep…from, stop…from, refrain from, be engaged in, look forward to, opposed to, depend on, thank…for, feel like, excuse…for, aim at, devote…to, set about, spend…in, get (be) used to, be fond of, be capable of, be afraid of, be tired of, be sick of, succeed in, be interested in, feel (be) ashamed of, be proud of, be keen on, be responsible for.