新人教版八年级下册英语动词不定式详细讲解12978

1、知识回顾l比较下列两组句子l第一组: Every morning i keep doing exercising l He practices playing tennis after school.l第二组: My friends want me to go out with him.l l Jack invites me to go shopping.不定式定义及构成(一) 动词不定式定义: 动词不定式是指动词的一种不带词形变化从而不指示人称、数量、时态的形式，属于非谓语形式。(二)动词不定式构成： to +动词原形 省“to”的不定式to+动词原形A: I want to buy som

2、e books.B: They wanted to buy some books.C: He decides to go home by himself.动词后省to的不定式(一)感官动词： see, watch, notice, look at，hear, listen to,feel . A: He saw some birds fall into the river.B: I often hear the girl sing in the next room.C: They looked at that person went into the store.动词后省to的不定式(二)使役

3、动词: make, let ,have.A: My mother makes me go to school .B: Let the boy go .动词后可省可不省“to”的不定式(三) 特殊动词HelpA: I often help my mother do house work.B: My classmates help me to learn English.不定式的否定形式l1.带to的动词不定式的否定lI want you to go now.lI want you not to go now.l直接在“to”前加notl2.省to的动词不定式的否定lLet the boy go

4、out .lLet the boy not go out .l直接在动词前加not动词不定式用法 动词不定式放在一些动词后面可以作宾语、宾语补足语、目的状语、表语等。 动词不定式用法 (一) 动词不定式作宾语 动词不定式可以放在一些动词后用作宾语，动词不定式作宾语的常用动词有:begin ask ,want ,forget ,remember ,learn ,hate 等。 A：I want to go home now . B: She forgets to take some medicine. C: My mother learns to dance.不定式作宾语结构lWant to d

5、o sth lNeed to do sthlDecide to do sthlLearn to do sthlWish to do sth lTry to do sthlHope to do sthlPlan to do sth 练习A: 我想买一些书。 I want to buy some books.B: 他们需要做更多的运动。 They need to do more exercise.C: 他希望离开学校。 He hopes to leave school.动词不定式用法(二)动词不定式作宾语补足语。动词不定式作宾语补足语表示宾语所做的动作，可以用动词作宾语补足语的动词有：tell ,

6、ask ,want ,invite ,encourage,help等。A: I want you to go now .B: Her parents wish her to be a teacher .C: He invites me to go swimming .动词不定式作宾补结构lAsk sb to do sthlInvite sb to do sthlTell sb to do sthlExpect sb to do sthlWant sb to do sthlWish sb to do sth lAdvise sb to do sth根据汉语完成句子:l 我们需要想出一个好计划l

7、We need _ _ _ _ a plan.l 我们每人打电话给10个人,请他们来.l We each _ _ ten people and ask them_ _.l 他们总是自愿贡献他们的时间来帮助他人.l They always_ their time _ _ other people.l 他咳嗽的厉害,他的医生让他戒烟.l He has a terrible cough. His doctor asked him _ _ _ smoking.动词不定式的用法(三)动词不定式作目的状语。 动词不定式作目的状语常用在go ,come ,hurry等不及物动词后，表目的。A: He went to see his sister yesterday.B: She goes to England to learn English .lThe girl could visit the sick kids in the hospital to cheer them up.lShe stills there once a week to help kids learn to read.lShe went home to have breakfast.lI make a lot of money to