陈洪青动词不定式.doc

动词不定式用法小结Unit5 的语法要点是动词不定式作宾语的用法。动词不定式是一种非谓语动词形式，其结构为“to+动词原形”，其中to是动词不定式符号，称为小品词，动词不定式没有人称和数的变化，它和其后的名词等构成不定式短语，在句子中可以用作主语、宾语、表语、补足语、定语、状语等。一、 动词不定式作宾语。常见的结构形式有：want to do sth.(想要做某事)；hope to do(希望做);expect to do(期望做); plan to do(计划做); like/love to do(喜欢做); afford to do(付得起); agree to do(同意做); ask to do(要求做); care to do(想要做); choose to do(决定做); decide to do(决定做); fail to do(未履行); help to do(帮助做); learn to do(学会做); manage to do(设法做); offer to do(主动提出); prepare to do(准备做); pretend to do(假装做); promise to do(答应做); prove to do(证明); refuse to do(拒绝做); resolve to do(解决); seem to do(觉得好像); volunteer to do(自愿做); wish to do(希望)。例如：1. Larry often helps to bring out the best in me. ()2. Still no one seemed to be bored. (P3 八上U1)3. I happen to know the answer to your question.我碰巧知道你那道问题的答案。4. The driver failed to see the other car in time. 司机没能及时看见另一辆车。 二、 动词不定式作主语。有时为了避免句子的头重脚轻，可以用“it”作形式主语，而把真正的主语动词不定式（短语）放在句子的后面。例如：1. To learn English well is not easy. = It is not easy to learn English well. 学好英语并不容易。 Its important to plant trees in spring. 在春天里种树很重要。2. Its not necessary to be the same. (P21 八上U3)3. Its always interesting to watch other people show their talents. (P29 八上U4)在动词不定式前加一个由介词for引导的短语，表示该动作是由谁来执行，称为不定式的复合结构。如： 1. Its good for us to read English in the morning. 对我们来说，每天早晨读英语是很有益2. Im shy so its not easy for me to make friends. (P21 八上 U3) 三、 动词不定式作表语,常用于be动词的后面。例如：1. His work is to drive a car. 他的工作是开车。2. The most important thing is to learn something new and have fun. (P18 八上 U3)四、 动词不定式作宾语补足语，如：1. He asked me to give him a book. 他让我给他一本书。 2. But my mother wants me to drink it (milk). (P12 八上 U2)五、 动词不定式作定语，通常放在所修饰的词后，为后置定语。1. Who was the first one to arrive? 谁第一个到的？2. The best way to learn English is to use it. 学英语最好的方法是使用它。3. , but we think the best way to relax is through exercise, (P13 八上 U2)4. And one great thing about them is that they give people a way to make their dreams come true. (P29 八上 U4)5. Mickey became the first cartoon character to have a star on the Hollywood Walk of Fame. (P37 八上 U5)6. Green Park is the best place to go to on weekends. (P31 八上 U4)7. Watching sitcoms is a great way to relax. (P39 八上 U5)动词不定式（短语）作定语修饰名词时，与其所修饰的词具有一种动宾关系。如果不定式中的动词为不及物动词时，其后要加上一个含义上所需要的介词。如：1. I have no chair to sit on. 我没有椅子坐。2. He has no house to live in. 他没有房子住。3. I have a lot of homework to do (vt.). 4. She has some clothes to wash (vt.). 六、 动词不定式作目的状语。如：1. They got up early to catch up the early bus. 他们早起去赶早班车。2. I just stayed at home most of the time to read and relax. (P2 八上 U1)3. I know she cares about me because shes always there to listen. (P21 八上 U3)4. because I want to get to Greenwood Park before 10:00 a.m. to meet my friends. (P31 八上 U4) 5. because almost everyone goes there to see the street performers. (P31 八上 U4)6. People went to the cinema to see the “little man” win. (P37 八上 U5) 有时可以把不定式（短语）提前，放于句首，表示强调目的，如：To learn English quickly and well, he went to England. 为了更快更好地学英语，他去了英国。七、 动词不定式和疑问词连用，可以作句子的主语、宾语、表语等。如：1. When and where to have the party is not known. 何时何地举行聚会还不知道。（主语）2. The problem is where to get a computer. 问题是从哪里找到电脑。（表语）3. No one knows how to do it. 没有人知道如何做这件事。（宾语）4. No one knows what to do. 没有人知道做什么。（宾语）形容词的最高级的用法在英语中，三者或三者以上的人或事物进行比较时，表示“最”的概念时要用形容词的最高级，最高级前一般要加the，并有介词或所有格表示比较范围，具体如下：1. 表示在某一场所中“最”，常和介词in连用。如：That book is the most expensive one in the bookstore. 那本书是书店里最贵的一本。2. 表示在不少于三者的同类中“最”，常和of或among连用，如：My movements are the most graceful of us three. 三个人中我的动作是最优雅的。3. 表示在已有的经验中“最”，后边常跟从句，如：Racing is the most interesting sport Ive ever known. 赛跑是我知道的最有趣的运动。Who is the most talented person you know? （P29 八上 U4）My cousin LiJing is the funniest person I know. （P28 八上 U4）4. 用代名词的所有格表示比较范围。You are always my fondest star. 你永远是我最喜欢的明星。最高级的使用中的注意事项：1. 在一些固定用法中，最高级前通常省略the,如：With best wishes for you. 向你致以最美好的祝愿。2. 表示“最高程度”的形容词，如：excellent, perfect, blind, dead, alone等，没有最高级，也不能用比较级。3. 最高级可被序数词或much, by far, nearly, almost, by no means, not quite, not really, nothing like等词语所修饰，如：This hat is by far the biggest. 这顶帽子是到目前为止最大的。How much did the second most expensive hat cost? 那顶第二贵的帽子值多少钱？4. 形容词最高级修饰作表语或介词宾语的名词、代词时，被修饰的词往往省略，如：He is the tallest (boy) in his class. 他是班上最高的（男孩）。5. 作状语的副词最高级前可以不加定冠词，如：Of all the boys he came (the) earliest. 所有的男孩中，他来的最早。6. 形容词最高级前通常要加定冠词the，而以下几种情况一般不需要加定冠词the：（1） 形容词最高级前有序数词、物主代词、指示代词或名词所有格等限定词修饰时，最高级前不用the，如： The Yellow River is the second longest river in China. 黄河是中国第二长河。（2） 形容词最高级在句中作表语而比较范围又不明确时，最高级前不用the，如： They are happiest on Saturdays. 他们在星期六最快乐。（3） 如果两个形容词最高级并列修饰同一个名词时，第二个形容词最高级前不加the，如： He is the youngest and tallest boy in his class. 他是班上年龄最小、个子最高的男孩。（4） 如果形容词最高级用来加强语气，作“十分；非常”之意时，前面不加the。但形容词最高级作单数名词的定语时，可用不定冠词a/an，如： That book is most interesting. 那本书非常有趣。（5） 作宾语补足语的形容词最高级前不加the，如： I found it most difficult to get to sleep. 我发现入睡最难。形容词比较级的用法1. 在比较级前可用much, even, still, a little, a lot 等修饰，但不可以用very, quite, pretty, rather等修饰。 Japan is a little larger than Germany. Theyre both small countries.2. 表示倍数： times + 形容词的比较级+ than Our room is twice larger than theirs. But theirs is more beautiful than ours.3 “大几岁”、“高几厘米”时用“表示数量的词+ 比较级”来表示。 I am two years older than you. Im taller than you.4. “比较级+and+比较级”表示“越来越” The earth is getting warmer and warmer. Its a world problem. Talent shows are getting more and more popular.5. “the+比较级，the+比较级”译为“越就越”The busier he is, the happier he feels. 他越忙越高兴。6. “the+比较级+of the two”译为“两个中比较的”He is the better of the two. Theyre both weak in English.注：有时不说出被比较对象，需要根据上下文的暗示来判断形容词的级别。如： - Are you feeling better now? - Yes, I feel well. Thank you.形容词原级和副词原级的用法1. 表示A和B两者比较，程度相同，用句型：A+动词+as+形容词原级或副词原级+as+BTom is as honest as John. Theyre both good stu