江西佳吉瓦多少钱一块:什么是英语中的“动词不定式”？

英语中动词的主要功能是做谓语，而动词不定式不能作谓语，所以叫动词的非谓语形式。动词不定式有两种形式，一是带to的不定式，一是不带to的不定式，后者都由动词原形构成。 不定式有动词的性质，有语态和时态。如：
一般式主动语态：to write 被动语态：to be written
进行式：to be writing
完成式：to have written 完成式被动语态：to have been written
动词不定式的动词性质还表现在可带宾语和状语组成不定式短语。例：Bill asked me not to say his name aloud.
(比尔要我别大声叫他的名字。有宾语和状语。）
不定式也有名词的性质，表现在可以在句中做主语、宾语、表语等。如：
To be content with little is true happiness.知足常乐。（主语）
She wants to improve her biology.她想提高她的生物学水平。（宾语）
He was the right man to marry Jane. 他正是要娶简的人。（定语）
动词不定式在句子中非常活跃，除了谓语之外所有的成分都能担当，位置往往灵活多变，要根据句子来具体分析，这大概是称为“不定”的原因吧。

to do
这种形式就是动词不定式

7. 动词不定式

7.1 不定式作宾语

1) 动词+ 不定式
afford aim appear agree arrange ask be decide bother care choose come dare demand desire determine expect elect endeavor hope fail happen help hesitate learn long mean manage offer ought plan prepare pretend promise refuse seem tend wait wish undertake
举例：
The driver failed to see the other car in time.
司机没能及时看见另一辆车。
I happen to know the answer to your question.
我碰巧知道你那道问题的答案。

2）动词+不定式 ； 动词+宾语+不定式
ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wish…
I like to keep everything tidy. 我喜欢每件东西都保持整洁。
I like you to keep everything tidy. 我喜欢你年使每件东西都保持整洁。
I want to speak to Tom. 我想和汤姆谈话。
I want you to speak to Tom. 我想让你和汤姆谈话。

3） 动词+疑问词+ to
decide, know, consider forget, learn, remember, show, understand, see, wonder, hear, find out, explain, tell
Please show us how to do that. 请演示给我们如何去做。
There are so many kinds of tape-recorders on sale that I can't make up my mind which to buy.有这么多的录音机，我都拿不定主意买哪一种。

注意:疑问词带不定式在句中作成分时，谓语动词用单数。
The question is how to put it into practice.
问题是怎样把它付诸实施。

to do

to 后面加动词原形

to do 后加动词原形
也可以叫to do 不定式

to＋动词原形

例句：

1．To talk with him is a great pleasure.

和他谈话是一件非常愉快的事。

(To talk with him是不定式短语，在句中作主语。)

2．Her job is to take care of the children and wash clothes.

她的工作是照看这些小孩和洗衣服。

(句中的不定式短语作表语。)

3．She decided to try again.

她决定再试一试。

(句中的不定式短语作宾语。)

4．I have a few words to say.

我有几句话要说。

(句中的不定式作定语。)

5．Peter came to China to study Chinese last year.

去年Peter来中国学汉语。

(句中的to study Chinese作came to China的目的状语。)

6．The doctor told him to take the medicine three times a day.

医生叮嘱他一天吃三次药。

(句中的不定式短语作宾语补足语。)

(2)不带to的不定式

例句

1．She made her children wash their hands before eating.

她要孩子们在吃东西前洗手。

(make sb. do中的do是不带to的不定式。)

2．Let's go swimming.

我们去游泳吧。

(Let sb. do中的do是不带to的不定式。)

3．I saw him cross the street.

我看见他横过马路。

(see sb. do这种在宾语之后接动词原形的句型，表示自动作的开始看到结束，是看到了动作的全过程。如果用see sb. doing则重点在于动作进行的状态。如：I saw a plane flying to the north. 我看见一架飞机正朝北方飞去。)

4．I helped him look for his key.

我帮他寻找钥匙。

(help sb. do = help sb. to do)

5．I had my daughter go instead.

我让我女儿替我去。

(have sb. do让某人做某事，do是不带to的不定式。)

6．Why not take a trip to Hainan?

为什么不去海南旅游呢？

(Why not do是无主语的特殊疑问句，表示一种建议。)

7．You had better not go out today.

今天你最好不要外出。

(had better do 最好……；had better not do 最好别……)

8．I felt the building shake.

我感觉到建筑物在摇晃。

常见到的不带to的不定式还有：

watch sb. do

notice sb. do

hear sb. do

listen to sb. do

look at sb. do

这几种结构中的do都可以被doing替换。do强调动作的全过程；doing强调正在进行的状态。