一、概述：虽然在研究生英语考试中并不直接涉及语法，但阅读理解，写作和翻译等试题无不体现出它的重要性。
然而，语法又是广大英语爱好者最难掌握的问题之一，市场上种类繁多的语法书籍，大凡都是内容多而不精，即次重点不分，对于在学习过程中，大家共同反映的较有难度的语法，如非谓语动词、虚拟语气、定语从句都未能作出精辟分析，使读者看后仍不知所云。
本着这个目的，我们再次相聚西安人信，希望通过两天的深入学习使广大考生对语法有个彻底的了解，，在今后考试中遇到相应问题能游刃有余。
二、重点语法再现：非谓语动词是动词的一种形式，就其定义而言，它在句中不能单独作谓语，非谓语动词包括动名词、分词和不定式，非谓语动词是语法学习中的重点也是难点，在历年的四、六级及其它考试中占有一定的分值，本单元将逐一重点说明。
I．分词（Participles）分词是一种非谓语动词，在句中不能单独作谓语，它包括现在分词（present participle）和过去分词（past participle）两种形式，这两种形式在句中的基本功能相同，主要起形容词和副词的作用，在句中做定语、状语、表语和补语，请看例句：All flights__ because of the storm, we decided to take the train.A．were canceled B. had been canceledC．having canceled D. having been canceled分析：此题多次在考研、四、六级考试中出现，是一个十分有难度的题，它所涉及到的语法也是方方面面，首先排除B 选项，因为过去完成时出现在主从复合句中，这个句中无连接词，从句意判断，“飞机取消应该是我们决定乘坐火车的一个原因”，所以句中all flights…the storm 在整个句中作一成份，即作状语表原因，既然是一成份就不是一句子，因而不能出现谓语动词，随之排除A 选项，飞机取消应该是被取消，所以排除 C 选项（表主动），答案为D选项（（表被动），选项中C、D分别为现在分词完成式的主动和被动式，动名词和现在分词形式相同，所以C、D也可称为动名词完成式的主动和被动动式，但由于动名词和现在分词最大区别在于动名词在句中不能作状语，因而排除动名词的可能性，由此引申出分词的时态。
(1)分词的时态和语态（Tense and V oice）（以动词do 为例）主动被动一般式doing being done现在分词完成式having done having been done过去分词done从上表中可看出，现在分词的一般式和完成式各有主动式和被动式，而过去分词只有一种形式，现在分词和过去分词在用法上的区别为前者表示正在进行的主动动作，后者表示已经完成的被动动作，而现在分词一般式和完成式的被动式则表示分词作状语时，分词的逻辑主语与句子主语之间的关系（这一点将在分词的用法中讲到），现在分词一般式表示动作与谓语动词动作几乎同时发生，而现在分词完成式则表示动作在谓语动词之前已经发生，如上述例句中“飞机取消在我们决定乘坐火车之前”，即having been canceled 的动作在decided 之前，另外分词在作状语前提下，现在分词完成式的被动式即having been done 等同于过去分词done，所以上述例句中也可以增加一选项canceled 也为正确选项(等同于D 选项having been canceled)(2)分词的用法(Usage)①定语：分词常用来修饰名词或代词，单个分词作定语放在所修饰词之前，分词短语作定语放在所修饰词之后，但有些过去分词也可放在所修饰词之后：a developing country（发展中国家）a developed country（发达国家）a boy standing by the door（站在门旁的男孩）a man moved by the film（一个被电影感动的人）注意：分词短语作定语置于句中时相当于一定语从句，如：Do you know that boy standing by the door? (相当于who is standing by the door)A man moved by the film (相当于who was moved by the film) is my father.②表语：分词或分词短语放在系动词be, become, get, remain, seem, stay后作表语，现在分词作表语表示主语的性质或正在进行的动作，过去分词作表语则表示主语所处的状态：The news is very exciting.（性质）He is reading English loudly.（正在进行的动作）The girl in red was deeply moved by what she had seen .（状态）③补足语：a 宾语补足语现在分词常放在感官动词: see, look at, hear, listen to, feel, smell, notice, observe, watch, find和使役动词：get, have, keep, set, send, leave后作宾语补足语。
过去分词常放在see, hear, watch, get, keep, leave, have, like, want, wish, order等词后作宾语补足语。
I saw him coming into the class.The screws are somewhere loose. I’ll have them tightened..b.主语补足语：把主动语态转换成被动语态，原先主动语态中的宾语补足语也相应地转变为主语补足语：He was seen coming into the classYou were not noticed waiting.④状语分词作状语是分词一重要用法，表示时间、原因、方式、条件、让步、结果和伴随情况，分词作状语时，其逻辑主语（表示分词动作发出者是隐含的））与句子主语保持一致，否则就会产生悬垂和荡空结构，另外分词作状语相当于一相应状语从句：如：Looking up at the sky, a bird was flying. 应改为：Looking up at the sky, I saw a bird flying.(When I was looking up at the sky…)（表时间）另外，为了表示明确时间或条件，有时可在分词前加when, while, if等连词：When compared with the size of the whole earth, the highest mountain does not seem high at all. (CET4-（3）分词否定式分词或分词短语表示否定意义时，将not 置于分词之前，不能放在分词之后：Not having received her letter, he decided to write another.（4）独立主格结构(Absolute Structure)分词作状语，分词的逻辑主语要与句子主语保持一致，即句子的主语便是它的逻辑主语，否则就会出现悬垂或荡空结构（前面已讲过），但有时分词有它独立的的逻辑主语，即分词的逻辑主语与句子主语不一致，这就是独立主格结构。
①独立主格结构公式：逻辑主语+ 分词（短语）+ 主谓A B在上述公式中，其中（逻辑主语+ 分词短语）属于独立主格结构，主谓是一完整句子，A、B 两主语不一致（A、B 由名词或代词充当），如前面所述例句：All flights having been canceled because of the storm, we decided to take the train. (All flights…the storm是独立主格结构部分，we decided …为一完整句子，all flights 和we 不属于同一主语，另外公式中分词短语也可用不定式、形容词等来代替。
)②独立主格结构具体构成：a.逻辑主语+ 分词（现在分词和过去分词）A new technique having been worked out, the yields as a whole increased by 20 percent. All things considered, the planned trip will have to be called off.b.逻辑主语+ 介词短语Mr. Wang came in, (with) a book in hand.c. with/without + 逻辑主语+ 分词With her hair dyed green, she looks like a clown.（小丑）Without anything left in the cupboard, she went out to get something to eat.d.逻辑主语+ 不定式The football game ended with Portugal team won, the details to be reported this evening.e.逻辑主语+ 形容词/副词The teacher stared at the student, his eyes full of doubt.He went out, no hat on.③独立主格结构用法：a.表时间：The shower being over, we went on our way. (When the shower was over, we…)b.表原因：All flights having been canceled because of the storm, we decided to take the train. (Because all flights had been canceled because of the storm, we…)c.表条件：Weather permitting, I’ll come to see you. (If weather permits, I’ll…)d.表伴随：A large fish was slowly swimming through the water, its tail swinging back and forth like the pendulum of a clock. (钟摆)（A large fish …,and its tail was swinging …）e.同位语（表示对前面名词作进一步解释）I have two sisters, one being a teacher, the other (being) a nurse. (I have …, one is a teacher,and the other is a nurse.)由此可见，独立主格结构和状语从句可互相转换，方法是首先在独立结构前加上相应的连词，其次把独立结构中的分词转变为谓语动词，反之亦然。