人教版八年级英语下册 《I'll help to clean up the city parks》PPT下载(第3课时)

人教版八年级英语下册《I'll help to clean up the city parks》PPT下载(第3课时)，共24页。

动词不定式

动词不定式是一种非谓语动词形式，在句中不能作谓语，没有人称和数的变化。

基本形式：to＋动词原形，有时to可以省略；否定形式：not + 动词不定式。 

动词不定式具有名词、形容词和副词的特征，因此可以在句中作主语、宾语、宾语补足语、定语和状语等。

作宾语

动词不定式（短语）可以放在一些动词后面用作宾语，能以动词不定式作宾语的动词有：begin, want, remember, agree, learn, like, decide, fail, pretend, demand, refuse等。

例如：

I want to tell you a story.

They begin to work at eight every morning.

Don’t forget to lock the door.

Would you like to go and have a picnic with us tomorrow?

作宾语补足语

动词不定式作宾语补足语，表示宾语所做的动作，可以用动词不定式作宾语补足语的动词有：tell, ask, want, like, invite, encourage, help等。

如：

The teacher asked us to read English for half an hour in the morning.

The teacher often tells Jim not to spend too much time playing computer games.

Please let me help you.

但在let, make, see, watch, hear, feel, notice, have等感官听觉动词或使役动词后面作宾语补足语的动词, 其不定式一般要省略动词不定式符号“to”，可以归纳为以下三种句式：

1.不可以省略to的不定式作宾语补足语:tell /ask / want / would like / wish /suppose / invite /encourage /teach/ depend on等 + sb.+ to do sth.  

例如：

The teacher told us to come earlier.

Tom invited me to his birthday party.

Her parents wish her to be a teacher.

2.省“to”的不定式作宾语补足语：let / make / have + sb. +do sth. 

例如：

Let the girl leave here now.

The boy made the baby cry.

see / watch / hear / notice / feel +sb.+do sth. 

例如：

I saw the students play basketball on the playground yesterday.

I often hear the girl sing in the next room.

... ... ...

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