動詞不定式用法 .doc

1、動詞不定式用法典型例題未編不定式是動詞的一種非限定式，它是不受主語的單復數、人稱、等的限定及影響的一種動詞形式，但有時態(tài)和語態(tài)的變化。一、動詞不定式的基本結構動詞不定式的基本形式為：to+動詞原形，有時可不帶to。不定式的否定形式是：not to+動詞原形。在句中除不能作謂語外，其他成分都可作。如：主語、表語、賓語、賓語補足語、定語和狀語等。注意：不定式之前的to（又稱為小品詞）與介詞to的功能不同。介詞to之后要接名詞或代詞的賓格，或相當于名詞的短語作它的賓語；而不定式符號to的后面需要跟動詞原形。speak to him (to 是介詞) 對他講話to speak English (to

2、是不定式的小品詞) 講英語二、動詞不定式的用法不定式在句中有各種作用，一般可歸類為三種基本用法：作名詞，作形容詞，作副詞。(一) 不定式作名詞的用法不定式起名詞作用，在句子中擔當主語、表語、賓語和賓語補足語。作主語名詞用法的不定式和名詞一樣，可擔任句子的主語。To grow more trees here is very important.(=It is very important to grow more trees here.) 在這里多種些樹是非常重要的。To hear your voice is so nice.(=It is so nice to hear your voice.

3、) 聽到你的聲音真高興。To speak English well is not easy for me.(=It is not easy for me to speak English.) 把英語說好對我來說并不容易。To walk to school takes me twenty minutes.(=It takes me twenty minutes to walk to school.) 步行到學校我要花20分鐘。注意：在It is to”的句型中，it是形式主語，真正的主語是不定式；使用這種結構，可以避免句子的頭重腳輕。通常不定式被視為第三人稱單數，所以動詞用is或was。It i

4、s bad for your eyes to read in the sun. 在陽光下看書對你的眼睛有害。另外，不定式作主語的句子，同時有另外一個不定式作表語時，不能轉換成 “It is to”的句型。To see is to believe. (百聞不如一見。)不能轉換為：It is to believe to see.2. 作表語不定式像名詞一樣，可以放在be動詞后面，形成表語。My work is to clean the room every day. 我的工作是每天打掃這間屋子。Her dream is to be a lawyer. 她的夢想就是成為一名律師。What they

5、want is to do it at once. 他們所想的就是立刻著手做這件事。附加： （1）動詞不定式往往放在系動詞be（，become, sound, taste 等系動詞后面一般不接不定式）的后面作表語，表示將來的情況，說明主語的內容。 例如： My wish is to become a teacher我的愿望是當一名教師。 Your job today is to clean the playground. 你今天的工作是打掃操場。 （2）如果系動詞后的動詞說明主語的性質，特征，相當于形容詞。這時就要用現在分詞作表語，而不用不定式。 例如： He said that the st

6、ory was interesting他說這則故事很有趣 Nurses responsibility is taking care of patients.3. 作賓語不定式作賓語用在及物動詞之后。常用的及物動詞有：want, wish, hope, like, begin, start, help, agree, refuse, promise, learn, forget, know, need, try等。They began to read and write. 他們開始讀和寫。She wanted to get home earlier that day. 她那天想要早一些到家。Th

7、ey refused to do so. 他們拒絕那樣做。I hope to visit Paris some day. 我希望有一天能參觀巴黎。注意：(1) 在某些復合賓語中，常用 “it”代替不定式，而把不定式放到后面去。He found it very difficult to get to sleep. 他發(fā)現很難入睡。She thinks it important to study English well. 她認為把英語學好很重要。(2) 在tell, show, teach, find out, decide, learn, forget等動詞之后，常用一個帶連接代詞或副詞的不定

8、式作賓語。He doesnt know which one to choose. 他不知道應該選哪一個。My mother used to teach me how to read and write. 過去我母親常教我如何讀書寫字。No one could tell me where to get this kind of bike. 沒人告訴我在哪里能找到這種自行車。不定式加疑問詞不止作賓語，還可作主語，表語，賓補4. 做賓語補足語She asked me to speak more loudly. 賓語 賓補Jim told him not to cry. 吉姆告訴他不要哭。She ad

9、vised him to do so. 她勸他這么做。We all know him to be a clever boy. 我們都知道他是一個聰明的孩子。He reminded me to lock the door when I left. 他提醒我離開時鎖上門。注意：重點記憶(1) 有一些表示感官的動詞，如see, hear, watch, feel, notice和某些使役動詞，如let, make, have等，其后跟不定式作賓語補足語時,不定式通常不帶to.He saw Li Ping come into the classroom. 他看見李平走近了教室。Dont forget

10、to let her leave earlier. 別忘了讓她早點走。It made me feel thirsty. 這東西讓我感到口渴。但當這些動詞用于被動語態(tài)時，作主語補足語的不定式要帶to. 例如：He was seen to come into the classroom. 他被看見走進了教室。I was made to do a lot of homework yesterday. 我昨天被要求做很多家庭作業(yè)。(2) 感官動詞后面還可用現在分詞作賓語。區(qū)別為：不定式表示動作發(fā)生了，側重全過程；現在分詞則表示動作正在進行。如：I saw him come in. 我看見他進來了。I

11、saw him coming補語，不是動名詞，動名詞只充當主語，表語，賓語，定語的成分 in. 我看見他正往里走。(3) 動詞help之后，帶to或不帶to都可以。Will you please help me (to) take this suitcase? 請你幫我提一下這個衣箱好嗎？She often helps her mother (to) clean their house. 她經常幫助她媽媽打掃房子。（二）不定式作形容詞的用法作定語1. 不定式有時起形容詞作用修飾名詞或代詞，在句中擔任定語。不定式作定語時，它的位置在它所修飾的名詞或代詞之后。I have a lot of wor

12、k to do. 我有許多事情要做。Have you got anything to say? 你還有什么要說的嗎？（something, anything, nothing, everything等復合不定代詞常用不定式做后置定語。）She is the last to come. 她是最后一個到的。（當名詞前有the first ,the last, the only 等以及最高級時：eg: She is always the first to come and the last to leave.)eg: He spoke loudly (only to / in order to/so

13、 as to) be heard.比較：He rushed to the station only to find the train gone .(結果狀語)注意：(1) 如果修飾不定代詞的還有形容詞時，它們的位置應該是：不定代詞+形容詞+不定式。I have something important to do. 我有些重要的事要做。Give me something hot to drink. 給我一些熱的東西喝。(2) 如果不定式是不及物動詞，或者不定式修飾的名詞或代詞是不定式動詞的地點、工具等，不定式之后要加一個介詞。This is the best room for you to l

14、ive in. 這是最適合你住的房間。There is nothing to worry about. 沒什么事情可擔心的。I want to borrow a piece of paper to write on. 我想借張紙寫字。(3) 不定式作定語時，一般可轉換為定語從句。The next train to arrive is from Shanghai. （to arrive=that will arrive）下一列到站的火車來自上海。附：不定式主動被動討論A)不定式修飾的名詞或代詞和不定式構成邏輯上的主謂關系時，不定式往往用主動形式. Have you got a key to un

15、lock the door? (A key unlocks the door) B)不定式和它前面被修飾的名詞或代詞構成邏輯上的動賓關系，又和該句主語構成邏輯上的主謂關系時，不定式常用主動形式 I have got a letter to write( I write letter) He needs a room to live in( He lives in a room) I know what to do( I do what) 但這句如改為下列形式，不定式就得用被動形式： I know what is to be done. 這是因為 what is to be done是賓語從句，

16、從句中的主語 what是動詞 do的動作對象 C)不定式作表語形容詞的狀語，和句中主語構成邏輯上的動賓關系時，不定式多用主動形式，這是因為人們往往認為形容詞后省去了 for one或 for people例如： He is hard to talk to( to talk to him) The book is difficult to understand. ( to understand the book.) 但如果強調句中的受事者時，亦可用不定式被動式，例如： The handwriting is very difficult to be read. The box is too hea

17、vy to be lifted D)在 “there十be” 的結構中，當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，如果說話人強調的是事情本身必須完成，則用被動形式 There is a lot of work to do. ( Somebody has to do the work) There is a lot of work to be done ( The work has to be done.) 請注意下面兩個句子的含義是不同的： There is nothing to do. 意為無事可做，感到十分乏味 There is nothing to be done意為某東

18、西壞了，無法使之恢復正常（三）不定式作副詞的用法不定式可起副詞的作用，在句中表目的、結果、原因等。1. 表目的He came to teach the little girl English. 他來給這個小女孩上英語課。I went to visit my uncle last Sunday. 上星期天我去拜訪了我的叔叔。In order to study English well, she often does more speaking and writing.為了把英語學好，她經常多說多寫。2. 表結果What has he said to make you so sad? 他說了什么話

19、讓你這樣傷心？They lifted a rock only to drop in on their own feet. 他們搬起石頭砸了自己的腳。3. 表原因I am sorry to hear that. 聽到這件事，我感到很難過。The question is quite difficult to answer. 這個問題很難回答。有時，還有表條件的用法三、動詞不定式的幾個重要結構1. 不定式的否定結構：not +to doHe told me not to be late. 他告訴我別遲到。She asked the old man not to be angry. 她請這位老人別生氣

20、。注意：不定式否定句不同于否定句形式。不定式否定句沒有助動詞，否定句有助動詞。I didnt ask him to come here. 我沒請他來。I asked him not to come here. 我請他不要來。2. 不定式的復合結構：for+名詞（代詞）+不定式It is very difficult for me to do this job. 對我來說做這件工作很困難。It is very important for you to practise your oral English in the daily life.在日常生活中練習你的英語口語是非常重要的。3. 不定式的

21、 “of+名（代）+不定式”結構It is very nice of you to help me. 你來幫我真是太好了。Its kind of you to think so much of us. 難為你這樣替我們想。It was careless of him to lose so many things. 他丟了這么多東西，真是太粗心了。4. 不定式的“疑問詞+不定式”結構此結構在句中的語法作用有以下幾點：(1) 作主語How to use the computer is a problem. 如何使用計算機是個問題。(2) 作表語The question is how to go t

22、o the park. 問題是如何去公園。(3) 作賓語I didnt decide where to go. 我還沒有決定去哪兒。注意：帶特殊疑問句的不定式可跟帶特殊疑問詞的賓語從句進行句型轉換。He didnt know what to do. =He didnt know what he should do.他不知道要做什么。(4) 作賓語補足語She often teaches me how to read and write. 她常教我如何讀書寫字。（5）作同位語The problem of which to select as his successor was quickly d

23、isposed of.5. 不定式的“too+形容詞或副詞+to do sth.”和 “too+形容詞或副詞+for sb/ sth +to do sth.”結構。She is too young to go to school. 她太小不能上學。This pair of trousers is too dirty for him to wear. 這條褲子太臟了，他不會穿他的。(1) tooto結構和tooforto結構連接句子的區(qū)別：tooto結構連接兩個單句中主語相同的句子。He is too tired. He cant go any further.He is too tired t

24、o go any further. 他太累了，再也走不動了。tooforto結構連接兩個單句中主語不相同的句子。The box is very heavy. She couldnt carry it.The box is too heavy for her to carry. 這個箱子太重了，她搬不動。(2) 這兩種句型還可用sothat(如此以至于)結構來連接,構成狀語從句.He is so tired that he cant go any further.The box is so heavy that he couldnt carry it.6. 不定式的 “(not)+形容詞或副詞+

25、enough to”結構和 “(not)+形容詞或副詞+enough for sb/ sth to do.”這種結構中不定式也用來作狀語表結果.意思是“能夠做某事”或“不能做某事”。He is old enough to join the army. 他到參軍的年齡了。The little boy doesnt study English well enough to understand you.這個小男孩英語學得不好，他不懂你的意思。這種結構可跟 “tooto”結構進行句型互換。This question was too difficult for everybody in our cla

26、ss to answer.這個問題太難了，我們班的所有人都回答不上來。This question was not easy enough for everybody in our class to answer.這個問題不太容易，我們班的所有人都回答不上來。四、省略動詞不定式符號to的幾種情況1. had better/ Why not? / Will you please?/ Shall we? / Let等句型后接動詞原形。2. 感官動詞see/ hear/ watch/ notice等和使役動詞make/ have/ let等后接動詞原形做賓補。3. help后接動詞不定式作賓補時的to

27、可省也可不省。4. would rather后接動詞原形。如：I would rather stay at home than go for a walk. 我寧愿呆在家里而不愿去散步。注意：為了避免重復，動詞不定式中與上文相同部分可以省略掉，但to須保持下來。與另外文檔矛盾，需證實(1) Will you join me in a walk? 你愿意和我一塊兒去散步嗎？Ill be glad to. 我愿意。(2) Did you find the reference books about it? 你找到有關的參考書了嗎？ -No, I tried to, but failed. 沒有。我

28、盡力了，但沒找到。不定式的時態(tài)、語態(tài)不定式都表發(fā)生在過去或現在的將來、目的或結果，有各種時態(tài)和語態(tài) 一般式 to do /to be done 完成式 to have done /to have been done 進行式 to be doing 完成進行式 to have been doing（根據語境來判斷該用何種時態(tài)和語態(tài)）（一）一般式表示動作通常與句子謂語所表示的動作或狀態(tài)幾乎同時發(fā)生，或是在它之后發(fā)生。 I am glad to see you. 不定式動作與句子的謂語動詞同時進行。一般式被動 Its an honour for me to be invited.（與句子謂語同時發(fā)生

29、） （這里為什么不用to invite,因為to invite不是修飾me的，不是定語，而是真正主語） （二）不定式的正在進行時，表前一個動作發(fā)生時，不定式所表動作正在發(fā)生Some dogs were found to be looking for food around. 一些狗被發(fā)現正在四處尋找食物。（三）不定式的完成式1）發(fā)生在謂語動詞的動作或狀態(tài)前，常接不定式完成式的動詞有 appear to have done seem to have done happen to(碰巧 have done be said to have done, be reported to have done be believed to