牛津译林版八年级英语上册Unit6语法知识点讲解(有答案)

牛津译林版八年级英语上册Unit6语法知识点讲解
【语法一动词不定式用作目的状语】
1.动词不定式作目的状语：
(1)动词不定式作目的状语，主要用来修饰动词，表示某一动作或状态的目的。

为了使目的意义更加清楚或表示强调意义时，还可以在前面加in order或so as,
其否定形式为: in order not/so as not+动词不定式。

【例句】
①He eats more fruit and vegetable in order to/so as to keep healthy.
为了保持健康，他吃更多的水果和蔬菜。

②I wrote it down in order not to forget. 为了不忘记，我把它写下来了。

(2)由in order to引导的目的状语，既可以置于句中，也可以置于句首; 而由so as to引导的目的状语，只能置于句中，而不能置于句首。

【例句】
为了及时赶到那里，他们很与早就出发了。

①They started early in order to/so as to get there in time.
②In order to get there in time, they started early.
2.动词不定式的复合结构作目的状语
当动词不定式有自己的执行者时，要用动词不定式的复合结构(即在动词不定式之前加“for+名词/宾格代词”)作状语。

【例句】
He opened the door for the children to come in. 他打开门让孩子们进来。

She bought several cakes for Harry to eat. 她给哈里买了几个蛋糕来吃。

3.目的状语从句与动词不定式的转换
在英语中，目的状语从句还可以转换为动词不定式作状语，从而使句子在结构上得以简化。

可分为两种情况:
(1)当目的状语从句中的主语与主句中的主语相同时，可以直接简化为动词不定式作状语。

【例句】
为了可以及时到达，我们会很早出发。

We'll start early in order that/so that we may arrive in time.
=We'll start early in order to/so as to arrive in time.
(2)当目的状语从句中的主语与主句中的主语不相同时,要用动词不定式的复合结构作状语。

【例句】
我早来是为了让你在会议之前读到我的报告。

I came early in order that you might read my report before the meeting.
= I came early for you to read my report before the meeting.
【例题解析】
（）Alan often goes to the old people's home up the old and look after them.
A.to cheer
B. cheer
C. cheers
解析:我们可用“句子结构分析法”解答此题。

结合选项可知句意为“艾伦经常去养老院让老人高兴并照看他们”。

故up the old and look after them是Alan often goes to the old people's home 的目的，故此处应用动词不定式短语作目的状语。

答案:A
【语法二动词不定式用作宾语补足语】
动词不定式充当宾语补足语时，表示的是宾语所发出的动作。

或用来表示宾语的状态、特性、身份等。

常跟这种复合宾语的动词有what, wish, ask, tell, order, beg, help, advise, allow prepare, cause,force, invite, encourage, need, teach, warn, expect等。

1.动词+名词(或代词)+动词不定式
【例句】
①The teacher wants us to become good pupils.老师希望我们成为好学生。

②I didn't expect you to arrive here so soon.我没有料到你到这儿会这么快。

[拓展]
1.谓语动词如果是使役动词make,let,have或感官动词(短语)see, hear, watch, notice, observe, feel, look at, listen to等，后面复合结构中的动词不定式不带to。

【例句】
①They made the boy go to bed early. 他们让那个男孩早睡。

②I don't want to let him come in. 我不想让他进来。

2.在一些感官动词后面既可以用现在分词，又可以用动词不定式构成复合结构，但两者有差别。

现在分词表示的动作正在发生，动词不定式表示的动作则已结束。

【例句】
①He saw the girl singing.他看见那个女孩正在唱歌。

②He saw the girl sing.他看见那个女孩唱歌了。

3.help后的动词不定式可加to也可不加to。

【例句】I'll help you (to ) carry the box. 我将会帮助你搬这个箱子。

【例题解析】
（）The traffic signs warn people after drinking.
A. to drive
B. not to drive
C. driving
D. don't drive
解析:我们可用“固定搭配法”解答此题。

warn sb. (not) to do sth.为固定搭配，意为“警告某人(不要)做某事”，在该结构中动词不定式作宾语补足语。

结合常识可知，交通标志应是“警告人们不要酒后驾驶”，故选B。

答案:B
【当堂小测】
1.She went to the market the birds.
A. watch
B. to watch
C. watching
D. watched
2. fail the final exam, he studies English day and night.
A. In order to
B.So as to
C. In order to
D.So as not to
3. Mary called and asked her husband home at once, because she locked their daughter in the home.
A. to leave
B.leave
C. go
D. to go
4. Let's for a walk, shall we?
A. to go
B.going
C. go
D.gone
5. Our teacher often tells us in the river. It's dangerous.
A. don't swim
B. not swim
C. not to swim
D. not swimming 答案：B C D C C。