2020动词不定式讲解及练习.ppt

How can you believe I can fly like a bird? To see ? _______is to believe. ? Its impossible for humans _________________now. to fly like a bird 不定式由“ to+ 动词原形 ”构成 , 其否定形式是 “ not/never to do ” , 不定式可以带宾语或状语 构成不定式短语 , 没有 ________ 的变化 , 但有 _______ 的变化。不定式可以作 ______________ ，但不能单独作谓语。不定式 的逻辑主语有时用“ for+ 名词或代词宾格 ”构 成。 不定式 人称和数 时态和语态 状语、表语和定语 主语、宾语、 一.结构 : to do ( 否定 ) not/never to do 二 . 时态与语态 主动语态 被动语态 一般式 进行式 完成式 完成进行式 不定式 to do to be done to be doing to have done to have been done to have been doing ---------- ---------- (1).They pretended not to see us. (2). He pretended to be sleeping. (3).She pretended to have known it before. ( 一般式表示与谓语的动作同时 / 几乎 / 发生在 它之后 .) ( 在谓语动词发生的同时 , 不定式的动作也正在进行 ) ( 完成式表示动作发生在谓语动作之前 ) (4).Were happy to have been working with you. ( 完成进行式表示谓语动作发生之前 , 不定式的 动作一直在进行而且可能之后也继续 ) 1. 作主语 2. 作宾语 3. 作宾语补足语 4. 作定语 5. 作状语 6. 作表语 7. 作独立成分 8. 与疑问词等连用 三 . 用法 / 功能 To see is to believe. It s important to learn English well . (1). 主语 ? 单个不定式作主语时 , 谓语动词用单数 ? 若不定式太长 , 往往用 it 作形式主语 , 不定式置后 . My job to help the patient. Your task to clean the classroom. is is (2). 表语 I want to go home. The workers demanded to get better pay. I found it necessary to talk to him again. (3) 宾语 think/ consider/ find it + adj.+ to do 常用动词不定式作宾语的动词有： hope, refuse, learn, set out choose, decide, agree, manage, pretend, plan. The teacher told me to clean the blackboard. I expect you to give me some help. (4). 宾补 五看 watch see look at observe notice 三使 let make have 二听 listen to hear 一感觉 : f eel warn, tell, allow, help, ask, force 等 e.g. I made him do his work. He was made to do his work (by me). 注意 1 help 后面的“ to” 可省去 e.g. They often help the grandma (to) carry water. 2 see, hear, watch, feel, notice, look at 等表示 感觉和 let, make, have 等表示使役的动词后 面，不定式作宾语时要省“ to” （注：被动 语态不省 to ） 3 不定式用在介词 but, except, besides 后时 , 如果这些介词前有行为动词 do 的 各种形式 , 那么介词后的不定式不带 to, 相反则带 to. (1). She could do nothing but cry . (2). I have no choice but to go . (3).What