动词不定式的基本用法归纳.ppt

4．作宾语补足语
【注意】在感官动词（see, hear, feel, listen to , notice, watch, observe等）和使役动词（let, have， make ）后的补足语中，不定式不带to。但这类 句子变成被动语态时，必须带to。
I saw him play in the park.
I think it necessary to report the thing to the teacher.
I find it interesting to work with him.
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C．动词不定式还可以用作介词宾语，但仅限于 介词except和but（除了）。 ❖常用句型有： There is nothing to do but+动词原形 do nothing but+动词（除做….之外别无选择） can but+动词原形 （只能原形(“只有做……) have no choice but to do ，只得） cannot help/choose but+动词原形(不能不……）
2.作宾语
A．动词后直接不定式作宾语的动词有许多，如 want, decide, intend, fail, wish, export, pretend, choose等等。
I mean to go there at once. B.不定式短语作宾语时，如果还带有宾语补足语，
往往把不定式短语放在宾补之后，而用it作形式 宾语。句型为“主语+find (feel, think, believe, consider, etc) +it+形容词/名词+to do sth”。
动词不定式的基本用法归纳
一、动词不定时的形式
❖肯定式：to do sth ❖否定式：not to do sth. ❖ 被动式：to be done ❖完成式：to have done
二、动词不定式的用法
1.作主语
A. 动词不定式作主语，谓语动词用单数形式。 如：
(1)To see is to believe.
(2)To master English gives us much help in the study of sience. B. 不定式或不定式短语作主语时，常用it作形 式主语，构成“It is + 形容词(+for sb.)不定式” 结构。
It is impossible for him to give up smoking.
→He was seen to play in the park.
The boss made those men work day and night.
→Those men were made to work day and night.
3．作表语和宾语不足语
❖ 动词不定式作表语，一是主语有不定式充当；二是 主语由抽象名词充当。
To teach is to learn. My job is to help the patient. 【注意】如果在主语中（通常在主语从句或修饰主语 的定语从句中）又实意动词do时，作表语的动词不 定式省略to。 All I want to do now (What I want to do now) is fill my stomach.