動詞不定式是高中學生英語學習的重點和難點,掌握好這一個重點,并突破這個難點,對于學生的高考很重要。因此,本文將從以下五個方面歸納且探究其用法。
一、動詞不定式的定義
不定式是動詞的一種非謂語形式,由不定式符號to+動詞原形構成。
二、不定式有以下幾種形式
1. to do sth.(一般時)
2. to be doing sth.(進行時)
3. to have done(完成時)
4. to be done(被動式)
5. to have been done(完成被動)
6. not (never) to do sth.(否定式)
三、不定式的特點
1.沒有人稱和數(shù)的變化,在句中不能做謂語(由于它為非謂語動詞),但是有時態(tài)和語態(tài)的變化。
2.仍保留有動詞的特點,即可有自己的賓語和狀語,和他們一起構成不定式短語。
3.具有名詞、形容詞和副詞的特點。
4.在句子中可以作下成分:主、賓、表、賓補、定、狀語。
四、不定式的具體用法
1.作主語,常用it做形式主語。To master a foreign language is necessary. → It is necessary to master a foreign language.
2.作賓語:
(1) vt.+to do sth.He decided to go to New York this summer vacation.以下這些動詞常用這個結構:hope wish want; demand ask; agree promise; manage learn decide; refuse pretend choose
(2) vt.+(疑問詞)+to do sth. I dont know what to do next.
(3) 如果作賓語的不定式太長,用it作形式賓語,而把不定式放在后面。I think it useful to learn English.
3.作表語, 說明主語的內(nèi)容。在多數(shù)情況下,不定式作表語可換為作主語。The most important thing is to work hard. = To work hard is the most important thing.
4.作賓補, 放在賓語之后。
(1) vt. sb. to do sth.→advise, ask, expect, order, require, teach, want, forbid, drive, permit, tell, warn, request, allow, cause, command, direct(指示), force, invite, lead, prefer, wish,He advised me to take more exercise and drink enough water every day.
(2) 使役動詞或感官動詞+ sb. do sth. →make, let, have; hear; see, watch, notice, observe; feel
He made me take more exercise every day.
5.作定語:
(1) 置名詞或代詞之后;(2) 在時間上尚未發(fā)生;(3) 與所修飾詞之間有邏輯上的主謂關系或動賓關系:He is the last man to leave the classroom.(主謂關系)I have a lot of work to do.(動賓關系)
6.作狀語:
(1) 表目的:in order to do sth. / so as to do sth. / to do sth.置句末時,其前無逗號, 置句首時不定式短語之后有逗號。注意:1)不定式或不定式短語表示的是主語的目的,所以不定式的邏輯主語必須與句子主語一致。2)如果不定式的邏輯主語和句子的主語不一致,則需要用for sb. 來引出其邏輯主語,構成不定式的復合結構。He opened the door for the students to come in.3)目的狀語從句與不定式的轉換:當目的狀語從句的主語與主句的主語一致時,從句作狀語可以轉換成不定式作狀語。so that 和in order that 引導目的狀語從句時,常與情態(tài)動詞can/could/may/might等連用。
(2)表原因:Im very glad / sorry to hear that.
(3)表結果:
1)熟悉 too + adj.+ to do sth 與so+ adj.+ that從句的轉換。
△He is too young to go to school=He is so young that he cant go to school.
2) only to do sth出乎意料的結果。
△He hurried to the station, only to find the train had gone.
△He hurried to the airport only to be told that the tickets had been sold out.
五、不定式的其它用法及特點
1. 不定式在but之后的用法
He has nothing to do but listen to some light music.
He has no choice but to sleep.
I cant but admire her courage and bravery.
= I cant help but admire her courage and bravery.
= I cant choose but admire her courage and bravery.
2. 不定式在adj. (easy, hard, difficult……)之后用主動表被動。 These problems are not easy to solve.
3. 不定式的省略。
1)當重復to do sth. 時,用to替代。I wanted to ride in the street, but my father told me not to.
2)當重復to be sth. 時,用to be替代。 —Would you like to be my friend? —Yes, Id like to be.
3)當重復to have done sth. 時,用to have替代。 —Do you know he finished his work? Yes! He is said to have.
總之,所有學生要通過歸納和探究的方式去學習動詞不定式的用法,并且通過大量的練習去鞏固其用法,這樣就可以輕松地掌握其用法和規(guī)律并應對高考。
【作者簡介】張靜,陜西省鎮(zhèn)安中學。