介词和介词短语的概念：

介词是一种用来表示词与词、词与句之间的关系的虚词，在句中不能单独作句子成分。介词后面一般有名词、代词或相当于名词的其他词类，短语或从句作它的宾语。介词和它的宾语构成介词词组，在句中作状语，表语，补语或介词宾语。介词可以分为时间介词、地点介词、方式介词和其他介词。

误用介词的三种情况：

1、多用介词：
多用介词可能是受汉语意思的影响将及物动词误用作不及物动词，也可能是受相关结构的影响而用错：
误：We discussed about the plan.
正：We discussed the plan. 我们讨论了计划。
误：Did he mention about the accident?
正：Did he mention the accident? 他提到那次事故了吗?
误：I saw her enter into the bank.
正：I saw her enter the bank. 我看见她进了银行。
误：He married with[to] a nurse.
正：He married a nurse. 他同一位护士结了婚。
误：How can contact with you?
正：How can contact you? 我怎么与你联系?
误：We should serve for the people heart and soul.
正：We should serve the people heart and soul. 我们应该全心全意地为人民服务。
误：Who controls over the factory? (但名词control可接over)
正：Who controls the factory? 谁管理这个工厂?
误：He has a great many of friends here. (比较a great number of)
正：He has a great many friends here. 他在这儿有很多朋友。

2、漏用介词：
漏用介词可能是受汉语意思的影响将不及物动词误用作及物动词，或是受相关结构的影响的影响而用错等：
误：This matter is difficult to deal. (deal with=处理)
正：This matter is difficult to deal with. 这事很难处理。
误：He is not a man to be depended.
正：He is not a man to be depended on. 他不是个可靠的人。
误：He took a cup of tea, and went on the story.
正：He took a cup of tea, and wentonwiththestory.他喝了一口茶，又接着讲故事。
误：My mother still regards me a child. (比较consider…as中的as可省略)
正：My mother still regards me as a child. 我母亲还把我当小孩看。
误：They insisted sending a car over to fetch us.
正：They insisted on sending a car over to fetch us.他们坚持要派车来接我们。
误：What he says is worth listening.
正：What he said is worth listening to.他的话值得一听。

3、错用介词：
错用介词的情况比较复杂，可能是因受汉语意思的而错，也可能是因弄不清搭配关系而错，可能是混淆用法而错，也可能是受相关结构的影响而错，可能是忽略语境而错，也可能是想当然的用错：
误：She called on his office yesterday. (call on+人，call at+地点)
正：She called at his office yesterday. 她昨天去了他办公室拜访。
误：He is engaged with a nurse.
正：He is engaged to a nurse.他与一位护士订了婚。
误：The sun rises from the east.
正：The sun rises in the east.太阳从东方升起。
误：Under his help, I finished it in time.
正：With his help, I finished it in time. 在他的帮助下，我及时做完了。
误：During he was in Japan, he visited many places.
正：During his stay in Japan, he visited many places.他在日本期间,参观过许多地方。
误：We are familiar to his character.
正：We are familiar with his character.我们了解他的性格。
误：Help yourself with the fruit.
正：Help yourself to the fruit.吃点水果吧。

介词的宾语：

 1、名词或代词作介词宾语：
如：Are you interested in history? 你对历史感兴趣吗？
        Don't worry about it. 别为它担心。
注：若是人称代词用作介词宾语，要注意用宾格。
如：No one can sing like her. 没有人能像她那样唱歌。(不能用like she)
2、动名词作介词宾语：
如：He is good at telling stories. 他善于讲故事。 
        In crossing the street he was run over. 他在穿过马路时被汽车撞倒。
3、过去分词作介词宾语：
如：We can't regard the matter as settled. 我们不能认为这事已经解决。
        I take it for granted you have read the book. 我以为你读过这本书。
注：过去分词用作介词宾语通常只见于某些固定结构中，如上面第1句涉及regard…as(认为…是)结构，第2句涉及take sth for granted(认为某事属实)。在其他情况下，介词后通常不直接跟过去分词作宾语，若语义上需要接过去分词(表被动)，可换用“being+过去分词”：
如：He went out without being seen by the others.他出去了，没有被其他人看见。
4、从句作介词宾语：
如：He was not satisfied with what she said. 他对她说的不满意。
        I'm worried about where he is. 我担心他上哪儿去了。
注：介词后通常不接that从句，遇此情况需考虑用其他结构：
误：He paid no attention to that she was poor.
正：He paid no attention to the fact that she was poor. 他根本不注意她很穷这一事实。
但有个别介词(如except)可接that从句。
比较：I know nothing about him except that he lives next door./I know nothing about him except for the fact that he lives next door. 我只知道他住在隔壁,其它的就不知道了。
5、不定式作介词宾语：
如：I had no choice but to wait. 除了等，我没有别的选择。 
       He wanted nothing but to stay there. 他只想留在那儿。
       They did nothing but complain. 他们老是一个劲地抱怨。 
       He never did anything but watch TV. 除了看电视，他从不干任何事。
注：(1)介词后接不定式的情形通常只见于but, except等极个别个词。该不定式有时带to，有时不带to，其区别是：若其前出现了动词do，其后的不定式通常不带to；
若其前没有出现动词do，则其后的不定式通常带to。 
(2)介词后虽然通常不直接跟不定式作宾语，但却可接“连接代词(副词)+不定式”结构：
如：He gave me some advice on how to do it. 对于如何做这事他给我提了些建议。
6、形容词作介词宾语：
如：Her pronunciation is far from perfect. 她的语音远不是完美的。
        In short, we must be prepared. 总而言之，我们要有准备。
        Things have gone from bad to worse. 事情越来越糟。
注：(1)有些形容词用作介词宾语可视为其前省略了动名词being：
如：He regarded the situationas(being) serious. 他认为形势严重。
        His work is far from(being) satisfactory. 他的工作丝毫不令人满意。 
(2)有些“介词+形容词”的结构已构成固定搭配：in full全部地，全面地，无省略地； in private私下地，秘密地； in particular特别地；in general一般地，通常地，概括地； in brief 简言之；in short总之，简言之； in vain徒然地，徒劳无益地；for fee免费地，无偿地； for certain肯定地，确切地；for sure肯定地，确切地； for short为了简短，简称；atl arge自由自在地，逍遥法外； by far…得多
7、副词作介词宾语：
如：I can't stay for long. 我不能久呆。 
        It's too hot in here. 这里面太热了。
        I looked every where except there. 除了那儿，我到处都看过了。
8、数词作介词宾语：
如：The city has a population of four million. 这座城市有四百万人口。
        He was among the first to arrive. 他是第一批到的。
9、介词短语作介词宾语：
如：Choose a book from among these. 从这些书中选一本吧。
        I saw her from across the street. 我从街的对面望见了她。
注：通常可后接介词短语作宾语的介词是from, till, until, since, except, instead of等。
比较：I took it from the bed. 我从床那儿(或床上)拿的。
            I took it from under the bed. 我从床下拿的。 
10、复合结构用作介词宾语：
如：She had no objection to Mary marrying him. 她不反对玛丽与他结婚。
        She came in with a book in her hand. 她手里拿着一本书走了进来。
        All the afternoon he worked with the door locked. 整个下午他都锁着门在房里工作。

介词短语的句法功能：
1、表语：
如：He was with a friend. 他和一个朋友在一起。
        Health is above wealth. 健康胜过财富。
        This knife is for cutting bread. 这把小刀是用于切面包的。
注：有些介词(如because of)引出的短语通常只用作状语，不用作表语：
误：His absence is because of the rain.
正：His absence is due to the rain. 他因雨未来。
但是，若主语是代词(不是名词)，becauseof引出的短语可用作表语：
如：It is because of hard work. 那是因为辛苦工作的原因。
2、状语：
如：Don't touch it with your hands. 别用手去摸它。
        Did you do this by design or by accident? 你这样做是有意的还是无意的？
3、定语：
如：This is his reply to your letter. 这是他给你的回信。
        This is the best way of doing it. 这是做此事最好的方法。
        My love for you is deeper than the sea. 我对你的爱比海深。
4、宾语补足语：
如：I found everythingin good condition. 我发现一切正常。
       Her illness kept her in bed for a week. 她因生病在床上躺了一星期。
注：用作宾语补足语的介词短语在相应的被动语态中则为主语补足语：
如：He was regarded as a hero. 他被看成是英雄。
5、宾语：
如：A man stepped out from behind the wall. 一个人从墙后走出来。
        He cannot spare anytime except on Sunday. 除星期日外，他抽不出时间。
6、主语：
如：Between6 and 7 suits me. 六点到七点对我比较适合。
        After the exams is the time to relax. 考试后是轻松一下的时间。
注：介词短语通常不用作主语，尽管有时也像上面这样用作主语，但通常可视为是在一定的上下文中有所省略：
如：—When are we going to have the next meeting? 我们下次什么时候见面？
        —On Tuesday may be convenient. 星期二可能比较方便。
此句中onTuesday虽用作主语，但可视为是其前省略了meeting一词：
即：Meeting during the vacation may be convenient.

动名词概念：

动名词是一种兼有动词和名词特征的非限定动词。它可以支配宾语，也能被副词修饰，动名词有时态和语态的变化。

现在分词和动名词用法比较：

动词的-ing形式包括现在分词和动名词两种形式。他们的句法功能如下：
动词的-ing形式如果作句子的主语或者宾语时，应该是动名词形式；如果作补语或者状语时，应该是现在分词形式。那么作表语或者定语的动名词和现在分词又该怎样区分呢？
1、动名词与现在分词作表语时的比较：
（1）动名词作表语说明主语的内容，回答what的问题；现在分词作表语相当于形容词作表语，说明主语的性质、特征等，回答how的问题。
如：One of the best exercises is swimming. 游泳是最好的运动项目之一。 
        What pleases him most is bathing in the sea. 最使他高兴的事是在海中沐浴。 
        The situation both at home and abroad is very in-spiring. 国内外的形势都很鼓舞人心。
        The color is pleasing to the eye. 颜色悦目。
（2）动名词作表语，表语和主语几乎处于同等地位，可以互换位置，其句意不变；现在分词作表语，表语和主语则不能互换位置。
如：Our work is serving the people.
      （＝Serving the people is our work.）我们的工作是为人民服务。 
        The news was disappointing. 那消息令人失望。
（3）作表语的现在分词前可以用very，quite，rather，greatly等副词修饰，而动名词则不可以。
如：What he said was very encouraging. 他的话很鼓舞人心。
        Our goal is realizing the four modernizations in the near future. 我们的目标是在不久的将来实现四个现代化。
（4）现在分词与形容词一样可以和more，the most构成形容词的比较级和最高级，而动名词则不可以。
如：The story is the most fascinating. 那个故事最迷人。
（5）作表语用的现在分词除了和be连用以外，还可以和其它的系动词连用；而作表语的动名词则通常只能和be连用。
如：His speech seems inspiring．他的演讲似乎很鼓舞人心。
        His interest is writing for the news papers. 他的爱好是给报社写文章。
（6）有些用作表语的现在分词已经形容词化了。常见的有：exciting，moving，inspiring，missing，interesting，disappointing等。
2、动名词与现在分词作定语时的比较：
（1）动名词作定语时，表示它所修饰的名词的性能和用途，和它所修饰的名词在逻辑上没有主谓关系；
现在分词作定语时，表示它所修饰的名词正在进行的动作，和它所修饰的名词在逻辑上有主谓关系，常可以扩展成一个定语从句。
如：a swimming girl＝a girl who is swimming 一个在游泳的姑娘
        a walking stick＝a stick that is used for walking 一根拐杖
（2）现在分词作定语有时可以后置，而动名词则通常只能放在它所修饰的名词之前。
如：The girl wearing glasses is one of his students. 戴眼镜的那个女孩是他的一个学生。
        I bought some reading materials. 我买了一些阅读材料。

 动名词的用法：

1、作主语：
例如：Fighting broke out between the South and the North. 南方与北方开战了。　
2、作宾语：　　
a. 有些动词可以用动名词作宾语。
例如：admit承认 appreciate感激 avoid避免 complete完成 consider认为 delay耽误 deny否认 detest讨厌 endure忍受 enjoy喜欢 escape逃脱 fancy想象 finish完成 imagine想象 mind介意 miss想念 postpone推迟 practice训练 recall回忆 resent讨厌 resume继续 resist抵抗 risk冒险 suggest建议 face面对 include包括 stand忍受 understand理解 forgive宽恕 keep继续
例如：Would you mind turning down your radio a little, please? 你把收音机音量调小一点，好吗？
      　 The squirrel was lucky that it just missed being caught. 这松鼠幸运得很，刚逃避了被逮住的厄运。　　　　　
b. 有些结构后面可以用动名词作宾语或其他成分。
例如：admit to  prefer...to   burst out   keep on   insist on   count on   set about   put off   be good at   take up   give up   be successful in   be used to   lead to  devote oneself to   object to  stick to  no good   no use be fond of   look forward to  be proud of   be busy   can't help  be tired of   be capable of   be afraid of   think of
3、作表语，对主语说明、解释：
例如：Her job is washing, cleaning and taking care of the children. 她的工作是洗刷、清扫和照顾孩子。
比较：She is washing, cleaning and taking care of the children.
4、作定语，一般表示所修饰名词事物的用途：
例如：a writing desk=a desk for writing 写字台
            a swimming pool=a pool swimming 游泳池
有些动名词作定语，与所修饰的名词关系比较复杂。
例如：boiling point=a temperature point at which something begins to boil 沸点
            a walking tractor=a tractor which a driver can operate while he or she is walking behind it 手扶拖拉机

动名词知识体系：

动名词与不定式用法对比：

强调句的概念：

强调句 (The Emphatic Pattern) 是一种修辞，是人们为了表达自己的意愿或情感而使用的一种形式。通过各种方式对句子中的某个部分进行强调，从而起到修辞的作用。英语常用的强调结构有：It is (was)+被强调部分(主语、宾语或状语)+that/who...；what…be…句型；

强调句的使用:

一、强调句句型：
1、用It is／was...that／who...句型表示强调。
（1）陈述句的强调句型：It is/was+被强调部分（通常是主语、宾语或状语）+that/who（当强调主语且主语指人）+其它部分。
e.g. It was yesterday that he met Li Ping.
（2）一般疑问句的强调句型：同上，只是把is/was提到it前面。
e.g. Was it yesterday that he met Li Ping?
（3）特殊疑问句的强调句型：被强调部分（通常是疑问代词或疑问副词）+is/was+it+that/who+其它部分？
e.g. When and where was it that you were born?
注：被强调的部分（通常是句子的主语、状语、宾语或宾语补足语）放在is／was的后面，如被强调的是人，则后面可用who，whom等代替。
如：原句：He met an old friend in the park yesterday.  
        强调主语：It was he who/that met an old friend in the park yesterday.
        强调宾语：It was an old friend that/who he met in the park yesterday. 
        强调地点状语：It was in the park that he met an old friend yesterday. 
        强调时间状语：It was yesterday that he met an old friend in the park.
2、用助动词do, does或did来强调谓语动词。
如：Do come early. 
        He did send you a letter last week.
        We're pleased that she does intend to come.
3、用主语从句+be+被强调部分，主语从句常用what引导。
如：What John wants is a ball.
        What Mary does every day is(to) give piano lessons.  

二、not...until...句型的强调句：
1、句型为：It is/was not until+被强调部分+that+其它部分：
e.g. 普通句：He didn't go to bed until/till his wife came back. 
       强调句：It was not until his wife came back that he went to bed.
2、注意：此句型只用until，不用till。但如果不是强调句型，till, until可通用；
因为句型中It is/was not...已经是否定句了，that后面的从句要用肯定句，切勿再用否定句了。

三、谓语动词的强调：
1、It is/was...that...结构不能强调谓语，如果需要强调谓语时，用助动词do/does或did。
e.g. Do sit down.务必请坐。
      He did write to you last week. 上周他确实给你写了信。
      Do be careful when you cross the street. 过马路时，务必（千万）要小心啊！
2、注意：此种强调只用do/does和did，没有别的形式；过去时用did，后面的谓语动词用原形。 

使用强调句型有以下几点请注意：

①强调句的谓语is或was永远用单数。
如：It was yesterday that I met your father in the street.
②不管被强调部分是哪种状语，只能用that连接，不得使用where、when等连词。
如：It was in the street that I met your father yesterday.
③被强调部分为人时，可用who(主格或宾格)和whom(宾格)代替that，用that也行。
如：It was your father that/whom/who I met in the street yesterday.
        It was I that/who met your father in the street yesterday.
④强调句中也要注意主谓一致、人称一致和否定转移的问题。
如：It is they who are our friends.
        It was not until ten o'clock that we got home last night.
⑤注意不要混淆强调句和其他从句。It is/was...that...为强调句标志，去掉后仍可组成一个完整的句子，只是没被强调，而其他从句一般不具备这一特征。
比较：1）It was ten o'clock when we got home last night. 我们昨晚到家时已十点了。
            2）It was at ten o'clock that we got home last night. 我们昨晚是在十点到家的。
第一句不是强调句，when不可改为that，因为去掉it was和that后，只能组成“We got home ten o'clock last night.”这样一个不完整的句子；第二句是强调句，that不可改为when。

强调句型用法拓展：

1、句首词用“It”，不能用“This”，“That”等。
2、be动词的形式是is或was，不能用复数形式are或were。若原句的谓语动词用了现在时或将来时，则用is；
若原句的谓语动词用了过去时或过去完成时，则用was。
如：It___the Chinese women that___a great role in the socialist construction.
A. is; plays
B. are; play
C .is; play
D. are; plays
答案：C 
3、被强调的部分如果是代词，强调主语用主格，强调宾语用宾格。
如：It is him that/who/whom I met in the street yesterday.
        It is I who/that am wrong.
4、连接词一般用that，当强调部分是人时，既可用that也可用who。特别注意当强调部分是时间状语或地点状语时，不能用when或where。
如：It was on Oct1st, 1949 that People's Republic of China was founded.
        It was at the gate____he told me the news.　　
        A. that
        B. what
        C. which
        D. when
答案：A
5、主谓一致问题被强调的主语要和that后面的谓语动词在数上保持一致。
如：It is Mary who often _____(help) me with my English. （helps）
        It is I that ____(be) against you. （am）
6、not...until结构的强调。
强调“not...until”引导的时间状语时，要用“it is/was not until...that...”结构，that后面的句子要用肯定式，且须用陈述句语序。 
如：We did not get off the bus until it stopped. ?
        It was not until it stopped that we got off the bus. (注意：强调该结构时not until不能分开)

虚拟语气的概念：

虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，不一定是事实，或与事实相反。在条件句中的应用条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。

虚拟语气在条件句中的应用：

一、真实条件句：
真实条件句真实条件句用于陈述语气，假设的情况可能发生，其中if是如果的意思。
时态关系句型：条件从句：一般现在时；主句：shall/will+动词原形
如：If he comes, he will bring his violin.
典型例题：
The volleyball match will be put off if it___.
A. will rain
B. rains
C. rained
D. is rained
答案：B。真实条件句主句为将来时，从句用一般现在时。
注意：1）在真实条件句中，主句不能用be going to表示将来，该用shall, will。
如： （错） If you leave now, you are never going to regret it. 
         （对） If you leave now, you will never regret it.
            2）表示真理时，主句谓语动词便不用shall(will)+动词原形，而直接用一般现在时的动词形式。

二、非真实条件句：
非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。 
1）时态：可以表示过去，现在和将来的情况。它的基本特点是时态退后。
a. 同现在事实相反的假设。
句型：从句：一般过去时；主句：should(would)+动词原形
如：If they were here, they would help you.
b.表示于过去事实相反的假设。
句型：条件从句：过去完成时；主句：should(would)have+过去分词
如：If she had worked harder, she would have succeeded.
        The rice would not have been burnt if you had been more careful.
        If my lawyer had been here last Saturday, he would have prevented me from going.
c.表示对将来的假想句型：
条件从句：一般过去时；主句：should+动词原形
                   从句： were+不定式；主句：would+动词原形 should+动词原形
如：If you succeeded, everything would be all right.
        If you should succeed, everything would be all right.
        If you were to succeed, everything would be all right.

三、混合条件句：
主句与从句的动作发生在不同的时间，这时主，从句谓语动词的虚拟语气形式因时间不同而不同，这叫做混合条件句。
如：If you had asked him yesterday, you would know what to do now. （从句与过去事实相反，主句与现在事实相反。）
        If it had rained last night (过去), it would be very cold today (现在).

比较if only与only if：

only if表示“只有”；if only则表示“如果……就好了”。If only也可用于陈述语气。
如：I wake up only if the alarm clock rings. 只有闹钟响了，我才会醒。
        If only the alarm clock had rung. 当时闹钟响了，就好了。
        If only he comes early. 但愿他早点回来。 
It is(high) time that It is(high) time that 后面的从句谓语动词要用过去式或用should加动词原形，但should不可省略。
如：It is time that the children went to bed.
        It is high time that the children should go to bed. 
need“不必做”和“本不该做"”
didn't need to do表示：过去不必做某事，事实上也没做。
needn'thavedone表示：过去不必做某事，但事实上做了。
如：John went to the station with the car to meet Mary, so she didn't need to walk back home.
        约翰开车去车站接玛丽，所以她不必步行回家了。   
        John went to the station with the car to meet Mary, so she needn't have walked back home.
        约翰开车去车站接玛丽，所以她本不必步行回家了。(Mary步行回家，没有遇上John的车。)
典型例题：
There was plenty o ftime. She___.
A. mustn't have hurried
B. couldn't have hurried
C. must not hurry
D. needn't have hurried
答案：D。needn't havedone. 意为"本不必"，即已经做了某事，而时实际上不必要。 Mustn't have done用法不正确，对过去发生的事情进行否定性推断应为couldn't have done,“不可能已经”。must not do不可以（用于一般现在时）

特殊的虚拟语气词should 的用法：

1）It is demanded/necessary/a pity+that…结构中的主语从句的谓语动词要用should加动词原形，should可省略。
句型：
如：It is suggested that we(should) hold a meeting next week.
        It is necessary that he(should) come to our meeting tomorrow.
2）在宾语从句中的应用在表示命令、建议、要求等一类动词后面的从句中。order, suggest, propose, require, demand, request, insist, command, insist+(should)do
如：I suggest that we(should) hold a meeting next week. 
       He insisted that he(should) be sent there.
注意：如suggest, insist不表示“建议”或“坚持要某人做某事时”，即它们用于其本意“暗示、表明”、“坚持认为”时，宾语从句用陈述语气。
如：The guard at gate insisted that everybody obey the rules.
判断改错：（错）You pale face suggests that you(should) be ill. 
                    （对）Your pale face suggests that you are ill.
                    （错）I insisted that you(should) be wrong.
                    （对）I insisted that you were wrong.
3）在表语从句，同位语从句中的应用在suggestion, proposal, idea, plan, order, advice等名词后面的表语从句、同位语从句中要用虚拟语气，即（should）+动词原形。
如：My idea is that we(should) get more people to attend the conference.
        I make a proposal that we(should) hold a meeting next week.

虚拟语气知识体系：

虚拟条件句的倒装：

虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had移到从句句首，实行倒装。
如：Were they here now, they could help us.=If they were here now, they could help us.    
        Had you come earlier, you would have met him=If you had come earlier, you would have met him.    
        Should it rain, the crops would be saved.=Were it to rain, the crops would be saved.
注意：在虚拟语气的从句中，动词“be”的过去时态一律用“were”，不用was，即在从句中be用were代替。
如：If I were you, I would go to look for him.  如果我是你，就会去找他。
        If he were here, everything would be all right. 如果他在这儿，一切都会好的。
典型例题：_____to do the work, I should do it some other day. 
                   A. If were I
                   B. I were  
                   C. Were I  
                   D. Was I
答案：C. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前，变成were, should, had+主语的形式。
但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说Were I not to do.，而不能说Weren't I to do。