前面有to了后面的可以省略
動詞不定式是由“to+動詞原形”構(gòu)成的.在實際運(yùn)用中,小品詞to在某些場合會被省略,下面簡要?dú)w納一下這些特殊情況.
1．在某些表示感官的動詞（組）如fell,listen to,hear,look at,see,watch,notic等的復(fù)合賓語中,動詞不定式不帶to.例如：
We often hear her sing this song.
我們經(jīng)常聽到她唱這首歌.
I saw him play basketball.
我見過他打籃球.
2．在使役動詞make,let,have等的復(fù)合賓語中,動詞不定式不帶to.例如：
Now let me hear you play.
現(xiàn)在讓我聽你演奏.
They made him work all day.
他們讓他整天工作.
注意：上述兩類句子若是變?yōu)楸粍诱Z態(tài),則原來作賓語補(bǔ)足語的不定式須帶to.例如：
She is often heard to sing this song.
He was made to work all day.
3．動詞help的復(fù)合賓語中,動詞不定式既可帶to,也可不帶to.例如：
Will you help me learn English?=Will you help me to learn English?
4．help后面的動詞不定式作賓語時也可省去to.例如：
Then he helped sweep the floor.
那時他幫助掃地.
The new policy has helped raise his wages.
新政策使他提高了工資.
5．當(dāng)兩個或兩個以上不定式短語連用而且作用相同時,那么除第一個不定式短語用to外,其余的不定式短語可省略to.例如：
This article is easy to read and understand.
這篇文章淺顯易懂.
He taught us to read and write.
他教我們讀書、寫字.
但是,若是在對照的場合（即強(qiáng)調(diào)對比）時,則不可省去to.例如：
It is better to laugh than to cry.
笑比哭好.13:26 2009-5-10ryedu.net
6．在had better,would rather,why not…固定結(jié)構(gòu)中,動詞不定式不帶to.例如：
You’d better go home now.
你現(xiàn)在最好回家.
She would rather stay here.
她寧愿呆在這兒.
7.當(dāng)介詞but,except,besides前面有一個實義動詞do時,不定式在介詞之后可省去to.例如：
We can do nothing but wait.
除了等待之外,我們別無辦法.
What do you like to do besides play piano?
除了彈鋼琴之外,你還喜歡做什么?
8．如果不定式作表語,且主語部分有all,what,only或是最高級形容詞修飾的名詞和實義動詞do時,作表語的不定式可省去to.例如：
All you need to do now is have a good rest.
現(xiàn)在你所需要的是好好休息.
What I want to do is finish my homework.
我要做的是完成作業(yè).
The best way to do is wait till she returns.
最好的辦法是等她回來.
The only thing you can do is sleep.
你惟一可做的只有睡覺了.