非謂語動詞不定式專題講解

1、第二部分 不定式1. 不定式的三個結(jié)構(gòu)：即否定結(jié)構(gòu)、疑問結(jié)構(gòu)和復(fù)合結(jié)構(gòu)。否定結(jié)構(gòu)為“not (never) to do”；疑問結(jié)構(gòu)是特殊疑問詞“how (what, which, who, whether) to do”；注明：(無if to do和why to do)復(fù)合結(jié)構(gòu)是“for/ of +名詞（或代詞賓格）+ to do ”。2. 不定式的三個時態(tài)形式和兩個被動語態(tài)形式（可記憶為三時兩語）主 動式 被 動式 一般時to do /not to doto be done/not to be done進行時to be doing /not to be doing無完成時to have do

2、ne /not to have doneto have been done /not to have been done3. 動詞不定式的功能英語的句子成分有七種，即：主語，謂語，賓語，定語，狀語，補足語，表語。動詞不定式除去不能單獨作謂語以外，其他六種成分均可充當(dāng)。（1）作賓語：(1) 接不定式作賓語的系動詞：appear，seem, prove, turn out, get.(2) 接不定式作賓語的動詞:請牢記下列小詩：決心學(xué)會想希望，拒絕設(shè)法愿假裝。主動答應(yīng)選計劃，同意請求幫一幫。decide / determine, learn, want, expect / hope / wish,

3、 refuse, manage, care, pretend,offer, promise, choose, plan, agree, ask / beg, help 此外，afford, strive，demand，fail，happen，attempt 等也要用不定式作賓語。（3）做形式賓語結(jié)構(gòu)：consider，judge，believe,make, feel, think, find +it +adj.+ to do sthEg.I find it interesting to study history.（2）.不定式用作定語的幾種情況：（1）.用來修飾被序數(shù)詞、最高級或no, al

4、l, any 等限定的中心詞。如：He was the best man to do the job.Women and children were the first to get into the lifeboats. （2）用來修飾的詞是抽象名詞時，常見的有：ability, chance, idea, fact, excuse, promise, answer, reply, attempt, belief, way, reason, moment, time 等。如：Do you have the ability to read and write English ?I have t

5、o chance to go sight seeing. 注意：1作定語的不定式如果是不及物動詞，或者不定式所修飾的名詞或代詞是不定式動作的地點、工具等，不定式后面須有相應(yīng)的介詞。如：The Browns have a comfortable house to live in. There is nothing to worry about. Please give me a knife to cut with.Here is some paper for you to write on.但是，不定式所修飾的名詞如果是time, place 或way時，不定式后面的介詞習(xí)慣上省去。如：He h

6、ad no money and no place to live (in).We found a way to solve this problem (in). (3)目的和結(jié)果狀語不定式常用的句型：tooto do （太而不能）, enough to do（夠就能）, so as to do/in order to do（為了）， soas to do/suchas to do（如此結(jié)果）。在這些常用句型中，注意so as to /in order to，前一個不能用于句首，而in order to既可放在句首，也可放在句尾。soas to與suchas to的區(qū)別是：“so”后一般接形容詞

7、或副詞、可數(shù)名詞單數(shù)（so + adj.+ a/ an + n.）?！皊uch”后一般接可數(shù)名詞復(fù)數(shù)、不可數(shù)名詞和可數(shù)名詞單數(shù)形式（such + a/an + adj. + n.）。so many/few+可數(shù)名詞 除外so much/little+不可數(shù)名詞一些常見的固定搭配的插入語：To tell you the truthTo be frank/honestTo be exact/specificTo begin withTo make a long story short4.let/make/have/see/hear/notice/observe/listen to/look at/

8、watch/feel 這些動詞帶不定式作賓補時，省掉to, 若這些動詞以被動形式出現(xiàn)時，應(yīng)加上to。動詞help后面作賓補的不定式可省略to，也可加to。例：I saw him go upstairs. 被動形式是: He was seen to go upstairs.總結(jié)：它們是“吾看三室兩廳一感覺”5看（look at, see, watch, notice, observe）；3使（make, let, have）；2聽（listen to, hear）；1感覺（fell）。注明：以上動詞還可用現(xiàn)在分詞作賓語補足語（5+3+2+1-2+4）：即以上動詞除let, make 外都可以用現(xiàn)

9、在分詞作賓語補足語，此外find, catch, keep, lave 也可以用現(xiàn)在分詞作賓語補足語。如：At that time, I found him crying in the street. He was caught stealing. Im sorry to have kept you waiting for such a long time. The missing boys were last seen playing near the river. 5. but/except + to do/ do 結(jié)構(gòu)，要根據(jù)謂語動詞來確定其后面的形式。當(dāng)謂語動詞是do, does, d

10、id時，but后用動詞原形；謂語動詞是其他動詞時，but后用“to + 動詞原形”的形式。6. 不定式的邏輯主語要與主語保持一致To study a foreign language, practice is needed. 這個句子邏輯主語不一致，應(yīng)改為：To study a foreign language, one needs practice. 學(xué)習(xí)外語需要操練。7. 形容詞后一般用不定式（除busy, worth 兩個外）例如：A) You are sure to succeed. （你一定能成功。）B) Im sorry to have given you a lot of tro

11、uble.（對不起，給你帶來那么多麻煩。）C) He is busy preparing his lessons at present. （他現(xiàn)在正忙于預(yù)習(xí)功課。）8. 不定式作定語和表語時，有時需要在后面放上一個適當(dāng)?shù)慕樵~。A) This is a bench to sit on.（這是用來坐的凳子。）B) This room is comfortable to live in. （這個房間住起來很舒適。）9. 在“主語+系動詞+adj.+不定式”這個句型中，當(dāng)主語是不定式的邏輯賓語時，不定式不用被動，不能在動詞后再放賓語。例：The question is easy to answer.

12、（question是answer的賓語，不能說：The question is easy to be answered. 也不能說：The question is easy to answer it .）（二）不定式的相關(guān)句型：(1)have no choice/alternative but to do .(2)have nothing to do but do /do nothing but /except do.(3)had better do /would rather do /would sooner do /cant help but do /why not do(4)would

13、like do .rather than do .(5) there is no need to do .(6)it is said /known/reported/thought/considered/believed to do /be doing/have done(7)only to do /never to do(8)cant but do/cant help but do/cant choose but do(9) consider，judge，believe, make, feel, think, find +it +adj.+ to do sth(10)ability, cha

14、nce, idea, fact, excuse, promise, answer, reply, attempt, belief, way, reason, moment, time ,wish to do(11)be to blame, be to let 主動表被動(12)was /were +to have done, would (should)like to have done(13)intend ,mean,hope,plane,expect,want+to have done=had intended,meant,hoped.to do表示按原來的計劃，安排想要做，卻沒有發(fā)生的事

15、。三、不定式的主動和被動1不定式修飾的名詞或代詞和不定式邏輯上構(gòu)成主謂關(guān)系時，不定式往往用主動形式。如：Do you have a knife to cut the watermelon ?(A knife cuts the watermelon.)2不定式和它前面被修飾的名詞或代詞構(gòu)成邏輯上的動賓關(guān)系，又和該句主語構(gòu)成邏輯上的主謂關(guān)系時，不定式常用主動形式。如：She has a sister to look after. (She looks after her sister.)I know what to do. (I do what.)3不定式作表語形容詞的關(guān)語，和句中主語構(gòu)成邏輯上的動賓關(guān)系時，不定式多用主動形式，這是因為人們往往認(rèn)為形容詞后省去了for sb. 。如：This book is difficult to understand. This kind of fish is nice to eat. 4在there be 結(jié)構(gòu)中，當(dāng)說話人考慮的是必須有人去完成某件事時，不定式用主動形式；如果說話人