动词不定式是高考英语单项填空的考查热点。在历年的高考英语试题中频频出现，本文对不定式考点作一下剖析，希望能帮助学生掌握不定式的用法。
一、 不定式的时态与语态
1. 主动形式：一般式(to do)表示的动作通常与谓语所表示的动作(状态)同时发生，或是在它之后发生。例如：
① I want to have a cup of tea. 我想喝杯茶。(同时)
② We expect him not to come. 我们希望他不来。(之后)
完成式(to have done)表示的动作在谓语动词所表示的动作(状态)之前发生。例如：
She was said to have been rich. 据说她曾经富有过。
进行式(to be doing)表示当谓语动词所表示的动作发生时，不定式表示的动作正在进行。例如：
He pretended to be waiting for someone. 他装着在等人。
2. 被动形式：不定式的被动语态只有一般式(to be done)和完成式(to have been done)。表示不定式的逻辑主语是不定式所表示的承受者时，不定式一般用被动语态。例如：
① He asked to be sent to work in the country. 他要求派遣到农村去工作。
② He thought it an hour to have been invited to the party. 被邀请参加聚会他感到很荣幸。
二、 不定式用法
1. 不定式做主语
(1)不定式作主语时相当于一个名
词，表明动词表达的动作或状态。一般位于句首；但如果不定式短语太长，常用it做形式主语置于句首，而将不定式短语移到句子后面。
(2)不定式作主语既可用to do结
构，也可用疑问词+to do结构。不定式作主语时谓语动词用单数。例如：
① To learn English well is necessary. 学好英语是必要的。
② It is a great pleasure to see you. 见到你非常高兴。
③ When to start has not been decided. 何时动身还未决定。
2. 不定式做宾语
不定式作宾语一般表示未来的行为。
(1)常跟在下列及物动词之后：be-
gin, decide, hope, expect, wish, learn, play, explain, agree, care, beg, choose, force, fail, pretend, offer, prepare, refuse等。例如：
① I like to get up early. 我喜欢早起。
② I pretended not to have seen her. 我假装没看见她。
(2)在动词know, wonder, tell, teach, show, ask, forget, discuss, learn, find out等或一些介词后常跟疑问词what, which, how, where, when以及连接词whether与带to的不定式连用。例如：
① Please tell me how to answer the question. 请告诉我该如何回答这个问题。
② I asked him whether to leave or to stay. 我问他要离开还是留下来。(此句中的whether不可用if替换)
(3) 在remember, forget, mean, regret, can't help, try等动词后接不定式作宾语与分词(-ing)作宾语有所不同。
remember/forget/regret to do sth. 记住/忘记/遗憾去做某事。
remember/forget/regret doing sth. (=to have done/having done sth.)记得/忘记/后悔做了某事
can't help to do sth. 不能帮助做某事
can't help doing sth. 禁不住做某事
try to do sth. 设法去做某事(不一定成功)
try doing sth. 试图做某事
mean to do sth. 打算做某事
mean doing sth. 意味着做某事
3. 不定式做宾语补足语或主语补足语
(1)下列动词后常用带“to”的不定式做宾语补足语，ask, allow, advise, beg, expect, enable(使能够),cause, get, invite, force, order, find, like, believe, teach, know, permit, call on等。例如：
① The teacher asked the students to put the text into Chinese. 老师要求学生将课文译成汉语。
② I know him to be a good leader. 我知道他是一位好领导。
(2)在下列动词后不用带“to”的动词不定式做宾语补足语，feel, hear, notice, observe, see, watch, let, have, look at, listen to等。但这类句子改为被动语态即不定式做主语补足语时，不定式符号“to”仍保留。例如：
I often hear him read English aloud. (宾语补足语)
He is often heard to read English aloud. (主语补足语)
4. 不定式做状语
(1)不定式做状语时，通常表示目的、结果、原因等。例如：
① To make a living, he works all day long. 为了谋生他整天工作。
② We must use these glasses carefully so as to not to break them. 我们必须小心使用这些玻璃杯以便不会打破。
③ His father left home, never to return. 他父亲离开了家再也没回来。
④ I was a fool not to listen to you at the time. 我当时不听你的话，真是傻瓜。
(2)形容词或过去分词作表语时，后面可接不定式作状语，用以说明产生这种情绪的原因或谓语所表示的情况等。用于这种结构中的形容词或过去分词常见的有glad, happy, lucky, sorry, ready, angry, proud, anxious, surprised, clever, foolish, pleased, right, easy, difficult, hard, comfortable等。例如：
① I am glad to hear the news. 听了这个消息，我很高兴。
② I was surprised to see her there. 我真想不到会在那里见到她。
③ He is easy to get along with. 他很平易近人。(待续)
