初中英语语法知识讲座

wangluo

第4章 助动词
一.概念:
助动词是帮助主要动词构成各种时态,语态,语气以及否定或疑问结构的动词.助动词分为时态助动词和结构助动词两种.
二.相关知识点精讲:
1. 助动词be的用法
1) be +现在分词,构成进行时态.例如:
They are having a meeting. 他们正在开会.
English is becoming more and more important. 英语现在越来越重要.
2) be + 过去分词,构成被动语态.例如:
The window was broken by Tom.. 窗户是汤姆打碎的.
English is taught throughout the world. 世界各地都教英语.
3) be + 动词不定式,可表示下列内容:
a. 表示最近,未来的计划或安排.例如:
He is to go to New York next week.. 他下周要去纽约.
We are to teach the freshmen. 我们要教新生.
说明: 这种用法也可以说成是一种将来时态表达法.
b. 表示命令.例如:
You are to explain this. 对此你要做出解释.
He is to come to the office this afternoon. 要他今天下午来办公室.
c. 征求意见.例如:
How am I to answer him 我该怎样答复他
Who is to go there 谁该去那儿呢
d. 表示相约,商定.例如:
We are to meet at the school gate at seven tomorrow morning. 我们明天早晨7点在校门口集合.
2. 助动词have的用法
1)have +过去分词,构成完成时态.例如:
He has left for London. 他已去了伦敦.
By the end of last month, they had finished half of their work. 上月未为止,他们已经完成工作的一半.
2)have + been +现在分词,构成完成进行时.例如:
I have been studying English for ten years. 我一直在学英语,已达十年之久.
3)have +been +过去分词,构成完成式被动语态.例如:
English has been taught in China for many years. 中国教英语已经多年.

wangluo

3.助动词do 的用法
1)构成一般疑问句.例如:
Do you want to pass the CET 你想通过大学英语测试吗
Did you study German 你们学过德语吗
2)do + not 构成否定句.例如:
I do not want to be criticized. 我不想挨批评.
He doesn't like to study. 他不想学习.
In the past, many students did not know the importance of English.
过去,好多学生不知道英语的重要性.
3) 构成否定祈使句.例如:
Don't go there. 不要去那里.
Don't be so absent-minded. 不要这么心不在焉.
说明: 构成否定祈使句只用do,不用did和does.
4)放在动词原形前,加强该动词的语气.例如:
Do come to my birthday party. 一定来参加我的生日宴会.
I did go there. 我确实去那儿了.
I do miss you. 我确实想你.
5)用于倒装句.例如:
Never did I hear of such a thing. 我从未听说过这样的事情.
Only when we begin our college life do we realize the importance of English. 进了大学以后,我们才认识到英语的重要性.
说明: 引导此类倒装句的副词有never, seldom, rarely, little, only, so, well等.
6)用作代动词.例如:
---- Do you like Beijing --你喜欢北京吗
---- Yes, I do. --是的,喜欢.(do用作代动词,代替like Beijing.)
He knows how to drive a car, doesn't he 他知道如何开车,对吧
4. 助动词shall和will的用法
shall和will作为助动词可以与动词原形一起构成一般将来时.例如:
I shall study harder at English. 我将更加努力地学习英语.
He will go to Shanghai. 他要去上海.
说明:在过去的语法中,语法学家说shall用于第一人称,will 只用于第二,第三人称.现在,尤其是在口语中,will常用于第一人称,但shall只用于第一人称,如用于第二,第三人称,就失去助动词的意义,已变为情态动词,试比较:
He shall come. 他必须来.(shall有命令的意味.)
He will come. 他要来.(will只与动词原形构成一般将来时.)
5.助动词should, would的用法
1)should无词义,只是shall的过去形式,与动词原形构成过去将来时,只用于第一人称.例如:
I telephoned him yesterday to ask what I should do next week. 我昨天给他打电话,问他我下周干什么.
比较:"What shall I do next week " I asked. "我下周干什么 "我问道.
可以说,shall变成间接引语时,变成了should.
2) would也无词义,是will的过去形式,与动词原形构成过去将来时,用于第二,第三人称.例如:
He said he would come. 他说他要来.
比较:"I will go," he said. 他说:"我要去那儿."变成间接引语,就成了He said he would come.原来的will变成would,go变成了come..

wangluo

6. 短语动词
动词加小品构成的起动词作用的短语叫短语动词.例如:
Turn off the radio. 把收音机关上.(turn off是短语动词)
短语动词的构成基本有下列几种:
1)动词+副词,如:black out;
2)动词+介词,如:look into;
3)动词+副词+介词,如:look forward to.构成短语动词的副词和介词都统称为小品词