非謂語動詞歷來是高考中的重點，不定式結(jié)構(gòu)在考點中常占很大比重。其中TO的用法很復雜，現(xiàn)就TO在一些結(jié)構(gòu)中常被省略的情況作如下小結(jié)。
1．感官動詞和使役動詞在主動語態(tài)中不需要帶to，即我們常說的“一覺二聽三讓五看”：feel,　listen to 、hear ,let、make、have, see、watch、notice、observe、look at.
He noticed Tom take a branch of flowers in his hand.
　　他注意到湯姆手中拿著一束鮮花。
The teacher has us write a composition every week.
　　老師要我們每周寫一篇文章。
    注：　除let 外其他在變成被動語態(tài)時要加上to。
The person was seen to enter the shop by us . 
　　我們看見那個人進了那家商店。
2　由 all， what 引導的主語從句或者主語被only, first, one, least 或形容詞最高級修飾時，而且從句中含有do時，其表語如果是動詞不定式，則往往省去to。
All I did was empty the bottle.
我所做的是倒空這個瓶子。
What I wanted to do was drive all night.
我想做的是徹夜開車。
The only thing I could do was do it myself 。
我惟一能做的是我自己解決。
3．常用的結(jié)構(gòu)　may well do，may as well do (還是…好了)及but或except后接不定式時，如果它們前面有do便可省略to，其結(jié)構(gòu)為can not do but…，can not help but…等句型，
We might as well put up here for tonight.
我們不妨今晚就在這兒過夜?！?br>She can do nothing but/except sing.
她除了唱歌什么也沒做。
There is nothing he could do but play all day long。
他除了整天玩，別無它事可做。
4．不定式做help后的賓語補足語或賓語時，可帶to也可不帶。
Can I help（to） carry it for you?
我可以幫你搬嗎？
I helped him（to） mend the bike.
我?guī)椭蘩碜孕熊嚒?
5．在had better，would rather，rather than之后省略to。
You'd better not tell him the news .　
你最好不把這個消息告訴他。
Rather than wait anyone, I decided to go home by taxi.
我決定乘出租車回家而不愿等候任何人。
6. 由并列連詞and，except, but, than, or 連接兩個以上的具有相同意義或功能的不定式時，第二個動詞不定式不帶to。
I’d like to stay with you, help you and learn from you.
我想留下和你一起呆著，幫助你并且向你學習。
She told us to stay at home and wait till she came back.
她告訴我們呆在家里一直等到她回來。
　　注：如果兩個不定式表示對照或?qū)Ρ葧r，則不能省略to.
To try and fail is better than not to try at all.
嘗試而失敗也比不嘗試好。
He hasn′t decided whether to quit or to stay.
他還沒有決定是去還是留。
To be or not to be, that is a question.
是生存還是死亡，這是一個問題。
7 以Why或Why not 開頭表請求的結(jié)構(gòu)中常跟上動詞原形,省略to。
    Why not go out for a walk ?
為什么不出去散散步呢？
8  通常在discover, imagine, suppose, think等詞后作賓補時，可以省去to be。例如：　
 He is supposed （to be） nice.　他應該是個好人。

EXERCISES
1.You had better ______ your hair cut.
A. had   B. have   C to get   D to have
 2 We ______ put the meeting off for a week.
A can as well   B. will as well    C. shall as well    D . may as well
 3 He ______ live in the country than in the city.
A prefers    Blikes to    C had better   D. would rather
 4  The boy told his father that he would rather ______ an astronaut.
A. become   B. to become   C becoming   D  became
 5  Paul doesn't have to be made ___. He always works hard.　
 A. learn　 B. to learn　 C. learned　 D. learning
 6  --- 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　
 7     He wants to do nothing but ＿＿out.
?。?to go?。隆?go    Ｃ going　  Ｄgoes
 8     He wants to believe anything but___ the medicine.
     A to take     B take     C take           D  takes
   9　 Compared with women. men always prefer ____ at home rather than ____  so much time shopping .  
   A to finish ,to spend     B to finish ,spend   C finish ,spend   D  finish  ,to spend
 ANSWERS 　　
1  A , 2  D  ,3   D ,  4  A ,5   B  ,6   D , 7  B  ,8  C ,9  B.