動詞不定式是非謂語動詞的重要組成部分,在六級考試中非謂語動詞部分是一個重點。以下重點為大家講解動詞不定式,希望對大家有所幫助!
常跟不定式的動詞:agree,fail,promise,afford,ask,happen,resolve,attempt,hesitate,seek,long,threaten,claim,manage,trouble,consent,neglect,try,decide,offer,undertake,demand,plan,volunteer,determine,prepare,want,pretend,wish,endeavor,proceed,struggle 等,在瞭解了加 to 的單詞之後,我們來看一看在什麼情況下單詞 to 可以被省略。
1、在一般助動詞或者情態動詞之後 to 可以被省略。
2、在動詞 make,let,watch,see……之後作賓語的時候,to 可以被省略。
3、在 why 和 why not 之後 to 可以被省略,如:Why spend such a lot of time?(為什麼花這麼多時問?)和 Why not go right now?(為什麼不現在去呢?)
4、在 had better,had best,would rather,had sooner,cannot but,do nothing but 等結構後面 to 可以被省略。
下面看一道有關不定式的例題:
We sometimes imagine desert island_______a sort of paradise,where the sun always shines。
have be ng g
整個句子的意思是,我們有時候把荒島想象成天堂,那裡終日陽光普照。imagine 後面常跟 to be +形容詞(或者名詞或反身代詞)結構,根據這個知識點,正確答案為 B。
可以跟這種結構的動詞還有think,consider,believe,find,feel,know,declare,guess,prove,suppose 等。這個結構中的 to be 常可以省略,如:They found him guilty.(他們發現他有罪。)
【定義】
(語態)動詞和參與此動作的主語之間關係的一個術語。當主語是動作的發起者(或之一)時,稱為主動語態;
如果動詞不定式的邏輯主語是這個不定式所表示的'動作的承受者,不定式一般要用被動語態形式。如:
It's a great honour to be invited to Mary's birthday party.(不定式作主語是被動語態to be invited是被邀請)
It was impossible for lost time to be made up.(不定式作主語)
I wish to be sent to work in the country.(不定式作賓語)
Can you tell me which is the car to be repaired?(不定式作定語)
He went to the hospital to be examined.(不定式作狀語)
在There be結構中,修飾主語的不定式可用被動,也可用主動。如:There are still many things to take care of (to be taken care of).但有時兩種形式表達的意思不同,如:There is nothing to do now.( We have nothing to do now.) There is nothing to be done now.(We can do nothing now.)
【語法形式】
1) 現在式:一般現在時表示的動詞,有時與謂語動詞表示的動作同時發生,有時發生在謂語動詞的動作之後。一般為:動詞+ to do sth
He seems to know this.
I hope to see you again. = I hope that I'll see you again. 我希望再見到你。
2) 完成式:表示的動作發生在謂語動詞表示的動作之前。
I'm sorry to have given you so much trouble.
He seems to have caught a cold.
3)進行式:表示動作正在進行,與謂語動詞表示的動作同時發生。
He seems to be eating something.
4)完成進行式:
She is known to have been wreaking on the problem for many years.
一般在表示情緒的動詞後加to do也表將來
【疑問詞】
疑問詞who,what,which,when,where,whether,how後可接不定式構成不定式短語,在句中作主語、賓語、表 語等。如:
①When to leave for London has not been decided yet. (不定式在句子中做主語)
②Mr. Smith didn't know whether to leave or stay there. (不定式在句子中做賓語)
③I asked Professor Xu how to learn English well. (不定式在句子中做直接賓語)
④The question was where to get the medicine needed. (不定式在句子中表語)
以上例句中疑問詞+不定式部分,均可轉換為相應的從句形式。如:①When we shall leave…③…how I
could learn……
經常在這種結構中使用的動詞有:consider,decide,discover,explain,find out,forget,hear,know,lea rn,observe,understand,wonder等。