不定式

作宾语

常接不定式作宾语的动词：afford, agree, aim, attempt, appear, choose, claim, demand, decide, desire, determine, expect, fail, hope, hesitate, happen, intend, long, learn, manage, offer, order, plan, promise, pretend, prepare, refuse, seem, strive, seek, tend, threaten, want, wish, volunteer

作补语

1. 动词 + sb. to do sth.
   • advise, allow, ask, beg, cause, expect, force, forbid, get, order, permit, persuade, recommend, require, tell, want, warn, teach, wish
2. 感官动词：see, hear, feel, watch, notice, observe, look at, listen to
   • 主动：sb. do sth.
   • 被动：sb. be seen to do sth.
3. 使役动词：make, have, let
   • 主动：sb. do sth.
   • 被动：sb. be made to do sth.
4. there be 结构：I don’t want there to be any trouble.
5. 动词词组 + sb. to do sth.
   • wait for, arrange for, call on, depend on, rely on, count on

作定语

常接不定式作定语的词：

• ability, ambition, eagerness, freedom, willingness, need, courage, decision, desire, failure, promise, refusal, wish, chance, opportunity, right, time, way, the first, the second, the last, the only, 形容词最高级

与被修饰名词有动宾关系时，不定式可用主动表被动。

• He is a man to depend on.
• Would you give me some paper to write on?

与分词作定语的区别：

• to do / to be done（将来）
• doing / being done（进行/主语/事本身）
• done （条件）

作状语

1. 目的状语：
   • 逻辑主语须与主句主语一致
2. 结果状语：
   • so … as to …, such … as to …
   • too … to …（only, all, but + too 表示“非常”）
   • only to …, never to …（意外结果）
     • He hurried to the room only to find nobody there.

不定式的特殊用法与考点

1. 不定式作主语的重要句型

   • It is + adj. + (of/for sb.) to do sth.
     • of：用于描述人的品质（kind, rude, clever 等）
     • for：用于描述事物特征（important, difficult 等）

   You are adj.说得通且意思一致用of

   • It is + n. (a pleasure / an honor / a pity) + to do sth.

   • It takes sb. … to do sth.

2. 不定式完成式表示“本想做但未做”

   • 动词：hope, expect, intend, mean, want 等
     • I intended to have called on you. = I had intended to call on you.

3. 介词后不定式：but / except

   • 前面有 do → 省略 to
   • 前面无 do → 保留 to
   • He had no choice but to turn to the driver for help.
   • Sandy could do nothing but admit his mistake.

4. 主语含 do 时，表语不定式省略 to

   • What we need to do now is take some measures.

5. 疑问词 + to do

   • 相当于名词，作主语、宾语、表语
     • How to solve the problem will be discussed.

6. 不定式主动表被动

   • 在 have / there be / with 结构中：There is a lot of work to do.
   • 在表性质的形容词后（easy, hard, difficult 等）：He is hard to talk to.

   在前加for sb.

7. 不定式固定句型

   • Why do? / Why not do?
   • There is no need to do …
   • prefer to do … rather than do …
   • had better do / would rather do
   • 插入语：to be honest, to tell the truth, to make things worse 等

8. 不定式在被动结构中的用法

   • sb./sth. be said / known / reported / supposed / thought / considered to do / to be doing / to have done
   • sb./sth. seems / appears / happens / proves to do …

9. 不定式的省略

   • 在 expect, prefer, like, mean, want, forget, wish, hope, try, be glad 等后，用 to 代替整个不定式
   • 若动词为 be 或 have been，则 to 不可省略
     • —Are you a teacher? —I want to be.
     • —Have you finished? —I hope to have.

10. 不定式作评注性状语（插入语）

    • 不修饰句中具体成分，表示说话者的态度或评价，常用逗号隔开。
    • 常见： to be honest, to be frank, to make things worse, to begin with, to sum up, to be brief, to be exact, to cut a long story short, to put it simply, to make matters worse, to conclude