動(dòng)詞不定式E

5. 不定式作表語 

　不定式可放在be動(dòng)詞后面，形成表語。例如： 
　　 My work is to clean the room every day. 
　　 His dream is to be a doctor. 
6. 不定式作定語 

　 不定式做定語通常要放在被修飾的詞后。例如： 
　　　I have a lot of work to do.　 
　　　So he made some candles to give light. 
7. 不定式作狀語
1）目的狀語　 
To… only to (僅僅為了),　in order to,　so as to,　so(such)… as to… (如此……以便……) 
　　He ran so fast as to catch the first bus.　他飛快地跑以便趕上第一班車。 
　　I come here only to say good-bye to you.　我來僅僅是向你告別。 

2）作結(jié)果狀語，表事先沒有預(yù)料到的，要放在句子后面。 
　　What have I said to make you angry. 
　　He searched the room only to find nothing. 

3)　表原因 
　　I’m glad to see you. 

典型例題 
　The chair looks rather hard, but in fact it is very comfortable to ___.　 
　A. sit　 B. sit on　 C. be seat　 D. be sat on 
答案：B.　如果不定式為不及物動(dòng)詞，其后應(yīng)有必要的介詞。當(dāng)動(dòng)詞與介詞連用時(shí)，常位于形容詞+動(dòng)詞不定式結(jié)構(gòu)的末尾。
8. 用作介詞的to 

　　to 有兩種用法： 一為不定式+動(dòng)詞原形； 一為介詞+名詞/動(dòng)名詞, to 在下面的用法中是第二種，即to+ 名詞/動(dòng)名詞： 

admit to承認(rèn)，　　　　　confess to承認(rèn)， 
be accustomed to 習(xí)慣于，　 be used to 習(xí)慣于， stick to 堅(jiān)持，　　　　 turn to開始，著手于， devote oneself to 獻(xiàn)身于，　be devoted to 致力于， look forward to 盼望，　　　pay attention to 注意 

9. 省to 的動(dòng)詞不定式
1） 情態(tài)動(dòng)詞 ( 除ought 外，ought to)： 
2） 使役動(dòng)詞 let, have, make： 
3） 感官動(dòng)詞 see, watch, look at, notice , observe, hear, listen to, smell, feel, find 等后作賓補(bǔ)，省略to。 
　 
注意：在被動(dòng)語態(tài)中則to 不能省掉。 
　 I saw him dance.  
　=He was seen to dance. 
　 The boss made them work the whole night. 
　=They were made to work the whole night. 
4） would rather，had better： 
5） Why… / why not…： 
6） help 可帶to，也可不帶to, help sb (to) do sth： 
7） but和except：but前是動(dòng)詞do時(shí)，后面出現(xiàn)的動(dòng)詞用不帶to的動(dòng)詞不定式。 
8） 由and, or和than連接的兩個(gè)不定式，第二個(gè)to 可以省去： 
9） 通常在discover, imagine, suppose, think, understand等詞后，可以省去to be：　  
　　 He is supposed (to be) nice.　他應(yīng)該是個(gè)好人。 

舉例： 
　　 He wants to move to France and marry the girl. 
He wants to do nothing but go out. 

比較：　 He wants to do nothing but go out. 
　　 He wants to believe anything but to take the medicine. 

典型例題 
1) ---- I usually go there by train.　  
　 ---- Why not ___ by boat for a change?　 
　　A. to try going　 B.　trying to go　 C.　to try and go　 D.　try going
答案：D. why not 后面接不帶to 的不定式，因此選D。 

2） Paul doesn’t have to be made ___. He always works hard.　 
　 A. learn　 B. to learn　 C. learned　 D. learning  
　 答案：B. make后接不帶to 的動(dòng)詞不定式，當(dāng)其用于被動(dòng)時(shí)，to 不可省略。