不定式用法专讲
4. 作状语用的不定式
不定式常可用来作状语，修饰动词，表示行为的目的(a)、结果(b)或原因(c)，如：
a．They ran over to welcome the delegates. 他们跑过去欢迎代表们。
The vice-minister cut the ribbon to open the exhibition. 展览会开幕由副部长剪彩。
To do a good job, we must have the right tools. 要干好活工具要对头。
We must do everything we can to help them. 我们要尽一切力量帮助他们。
b．He made a long speech only to show his ignorance of the subject. 他讲了一大段话，只暴露出他对这门学科一无所知。
What have I said to make you so excited? 我说了什么话使你这样激动?
The curtain parted, to reveal a market scene. 帷幕分开，出现一个集市的场面。
She lived to be 100. 她活到一百岁。
He left, never to return. 他走了，再也没有回来。
C．We all rejoiced to hear of your success． 听说你们成功了我们都很高兴。
She shuddered to think of her bitter past. 她想起了辛酸的过去真是不寒而栗。
To hear him talk in that manner, you would think him a foreigner. 听他这样说话，你会以为他是外国人。
We jumped with joy to hear the news. 我们听到这消息高兴得跳了起来。
另外，不定式也常用在so as (to)或in order (to)后，与它合起来作状语用，表示目的:
Let's hurry so as not to be late for the meeting. 咱们快点走，免得开会迟到。
She decided to work harder in order (so as) to catch up with the others. 她决定加紧学习好赶上别人。
In order to achieve this aim, we must learn from other countries. 为了实现这个目标，我们必须向别的国家学习。
此外，还可和某些不及物动词连用：
My blood pressure tends to be high. 我的血压偏高。
They burned to avenge his death. 他们一心要给他报仇。
不定式也可用在作表语用由形容词(或过去分词)后面作状语，说明产生这种情绪的原因或是在哪方面存在谓语所表示的情况等：
I am sorry (glad) to hear it. 听了这个我很难过(高兴)。
He was annoyed to hear them talk like that. 听他们这样说话他很不高兴。
We are proud to be young people of China. 作为中国的青年我们感到自豪。
We shall be very happy to co-operate with you in the work. 我们将很高兴在这项工作中和你们合作。
We were surprised to find him there. 看到他在那里我们感到很惊奇。
We should "not feel ashamed to ask and learn from people below." 我们要"不耻下问"。
They are eager to take part in the work. 他们亟于参加这个工作。
We were grieved to learn of his death. 听说他去世我们都很悲痛。
She is always ready to help others. 她总是乐于帮助别人。
Be careful not to catch cold. 小心别着凉了。
I don't feel inclined to accept the invitation. 我不太想接受邀请。
You are very kind to say so. 谢谢你这样说。
能用在这类结构中的形容词和过去分词很多，常见的如：happy，lucky, fortunate, unfortunate, pained, ashamed, surprised, grieved, frightened, shocked, sorry, glad, delighted, able, unable, destined, apt, willing, unwilling, worthy, eager, proud, disappointed, angry, right, anxious, content, impatient, fit, ready, clever, unwise, naughty, quick, show, prompt, foolish, rude, thoughtless, (in) considerate, cruel, wrong等。
另外，在这种结构中还可以用easy， difficult, hard, comfortable等形容词，这时作句子主语的除了表示人的词外。还可以是表示事物的词：
The girl was easy to get along with. 这女孩很容易相处。
He is worthy to take the position. 他配得上做这项工作。
The question is rather difficult to answer. 这问题相当难回答。
A foreign language is as a rule hard to learn. 外国语一般不好学。
The room is comfortable to live in. 这房间住起来很舒服。
This water is not fit to drink. 这水不适于喝。
Thousands of words are inadequate to express how grateful we are to you. 千言万语也说不尽我们对你的感激之情。
在用这些形容词构成复合宾语时，也能用不定式作状语，如：
We found the house very comfortable to live in. 我们发现这房子住起来很舒服。
I don't think him hard to get along with. 我想他不难相处。
上面讲的句子，有些也可以改为下面这种形式：
This is a very comfortable house to live in. 这是一栋住起来很舒服的房子。
I think him a very nice person to get along with. 我想他是一位容易相处的人。
这时不定式就成了定语。
注： 下面句子中的不定式也是一种状语：
Take care not to catch cold. 小心别着凉。
He has made up his mind to put his heart and soul into the work. 他决定全心全意投入这项工作。
当一个句子里带有too或enough这样的词时，我们也常用一个不定式来作状语：
She was too young to understand all that. 她太年轻不能理解这些。
We found the room too small to hold so many people. 我们发现房间太小坐不了这么多人。
I am sorry I am too much in a hurry to talk with you. 对不起，我有急事要办不能和你谈话。
We found the room not big enought to hold so many people. 我们发现这房间不够大，坐不了这么多人。
She was not old enough to understand all that. 她年岁不够大，不能理解这一切。 Have you got enough room to seat all of us? 你们这儿坐得下我们所有这些人吗?
有时在so...as (to)这种结构中也可以用不定式作状语：
Be so kind as to drop in some time when you are free. 什么时候有空希望来我们家玩。
Was he so conceited as not to believe in the wisdom of the masses? 他会这样高傲，不相信群众的智慧?
注: 有时不定式可以用来说明说话人的态度，对整个句子进行解释：
To tell you the truth, I am not in favour of your plan. 说老实话，我不赞成你的计划。
To be frank, we don't trust him. 坦白地说，我们不信任他。
To be fair, he is not at all an irresponsible man. 说句公道话，他绝对不是一个不负责任的人。
To say the least, their techniques are old-fashioned. 说得再轻点，他们的工艺至少是太老了。
Among writers of his age, he was, so to speak, a giant among dwarfs. 在那时的作家中，他可以说是鹤立鸡群。
这类结构可称为句子状语，也可看作插入语。