文档介绍：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,没有人称和数的变化,但有时态和语态的变化。不定式可以作主语、宾语、状语、表语和定语,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 1结构: to do (否定) not/never to do 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).We ’ re 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: feel warn, tell, allow, help, ask, force 等 . 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 . 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 do you like to do besides sleep .