八年级上册Unit5Doyouwanttowatchagameshow不定式讲解及练习

1、动词不定式 动词不定式由“to 动词原形”构成，有时可以省略to。动词不定式在句中可作宾语、宾语补足语、状语、定语等。动词不定式在句子中不作谓语，所以没有人称、数和时态的变化，其否定式是在to前加上not。如：ask sb. not to do； tell sb. not to do；具体用法见下表：不定式结构作主语如果不定式较长，显得头重脚轻，则可由代词it作形式主语(形式主语it不可由that或this等其他代词代替)，而将不定式放到后面。不定式结构所表示的动作是谁做的，即不定式的逻辑主语，通常可以通过It is + adj. + for sb. to do sth. 在某些形容词(如ca

2、reless，clever，considerate，foolish，good，impolite，kind， naughty，nice，silly，stupid等)作表语时，不定式后可以加of来引导出其逻辑主语It is + adj. + of sb. to do sth. 不定式作宾语不定式作宾语有两种：一种是及物动词后直接跟带to的不定式， 另一种是“及物动词+疑问词+带to的不定式。及物动词+带to的不定式结构:只能跟动词不定式的动词，常见的有: afford， agree， aim， appear， ask， believe， care，claim，decide demand， desi

3、re， determine， expect， fail， happen， hesitate， hope， intend， learn， long， manage， offer， pretend， promise， prepare， refuse， seek， swear， undertake，want， wish等。口诀：同意提出做计划,要求答应来帮忙。准备决定遭拒绝,敢于选择有希望。不能做到莫假装,设法做成决心坚。不定式做表语一种情况为主语是不定式(表示条件)；表语也是不定式(表示结果)：To see is to believe.另一种情况为主语是以aim，duty，hope， idea，j

4、ob， plan，problem， purpose，thing，wish等名词为中心的短语，或以what引导的名词性从句，不定式表语对主语起补充说明作用：不定式作定语 不定式结构作名词词组修饰语主要有三种类型：第一种，被修饰的名词词组是不定式的逻辑宾语。如果不定式是不及物动词，后面就得加相应的介词。例如： needs a friend to play with第二种，被修饰的名词词组是不定式的逻辑主语；例如： you got a key to unlock the door?5)不定式作状语不定式结构在句中作状语通常都能转换为限制性状语从句。例如作原因状语： are quite surpris

5、ed to see the great changes taking place in the area6)作宾语补足语在teach，ask 等动词之后用不定式作宾补。在let，make和have之后用省略to的不定式作宾补( ) 1. _ the seeds and they will grow.A. Water B. To water C. Watering D. Watered( ) 2. The purpose of the scheme is not to help the employers but _ work for young people.A. provide B. to

6、provide C. providing D. provided( ) 3. He arrived at the office early, _ a good example to the others.A. set B. to set C. to be set D. having set( ) 4. Please make my excuse at tomorrows meeting Ive got too much work _.A. to do to comeB. doing comingC. to do comingD. to do coming( ) 5. We looked eve

7、rywhere for the keys, but they are nowhere _A. to findB. to have found C. to be found D. being found( ) 6. After describing the planned improvements, she went on _ how much they would cost.A. to explain B. explaining C. to be explainingD. having explained( ) 7. To test eggs, _ them in a bowl of wate

8、r: if they float theyre bad, if they sink theyre good.A. put B. putting C. to put D. to be putting( ) 8. Please remember _ the plants while Im away.A. wateringB. to be wateringC. to water D. being watering( ) 9. _ wine, first you must press the grapes.A. Making B. To makeC. To be making D. Makeith you, Jim or Jack?A. have go B. h