人教版八年級英語下冊《I'll help to clean up the city parks》PPT下載(第3課時)，共24頁。
動詞不定式
動詞不定式是一種非謂語動詞形式，在句中不能作謂語，沒有人稱和數的變化。
基本形式：to＋動詞原形，有時to可以省略；否定形式：not + 動詞不定式。
動詞不定式具有名詞、形容詞和副詞的特征，因此可以在句中作主語、賓語、賓語補足語、定語和狀語等。
作賓語
動詞不定式（短語）可以放在一些動詞后面用作賓語，能以動詞不定式作賓語的動詞有：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?
作賓語補足語
動詞不定式作賓語補足語，表示賓語所做的動作，可以用動詞不定式作賓語補足語的動詞有：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等感官聽覺動詞或使役動詞后面作賓語補足語的動詞, 其不定式一般要省略動詞不定式符號“to”，可以歸納為以下三種句式：
1.不可以省略to的不定式作賓語補足語: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”的不定式作賓語補足語：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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關鍵詞：I'll help to clean up the city parks PPT課件免費下載，.PPT格式；
