(1)疑问词+不定式结构 [iVCorU
疑问词who,what,which,when,where和how后加不定式可构成一种特殊的不定式短语。它在句中可以用作主语、宾语、表语和双重宾语。如: 6U
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When to start has not been decided.何时动身尚未决定。(主语) W>3[+w
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I don't know what to do.我不知道该怎么办。(宾语) R~OameRR
The difficulty was how to cross the river.困难在于如何过河。(表语) x Vk|6vA7
I can tell you where to get this book.我可以告诉你哪里可以买到此书。(双重宾语) rMRM*`Q2
(注)A.有时疑问词前可用介词,如: a+A^njk
I have no idea of how to do it.我不知道如何做此事。 ,#&\1Vxf
B.动词know 后面不能直接跟不定式作宾语,只能跟疑问词(如:how, what)+不定式: (IdXJvKU!
While still a young boy, Tom knew to play the piano well and as he grew older, he wrote operas, the most famous of which is Carmen. tPu0r],`o
(2)介词except和but作“只有…,只能…”讲时跟不定式结构(but与不带to的不定式连用)。 ?+#|h;M8
When the streets are full of melting snow, you cannot help but getting your shoes wet. }
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(3)不带to的不定式 l&3f<e
1)在表示生理感觉的动词后的不定式不带to。这类词有: `-a](0QU
feel 觉得 observe 注意到,看到 overhear听到 g}>Sc=e<
watch注视 listen to听 perceive察觉,感知 '
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notice注意 see看见 look at看 hear听 Z*&y8;vUQ
On seeing the young child fell into the lake,Eric sprang to his feet,and went on the rescue. V1y"
2)另一类是某些使役动词,如make, let,have等。如: K_/-mwA v
Let him do it.让他做吧。 TZ
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I would have you know that I am ill.我想要你知道我病了。 ~*:{U
(注): Ky"]L~8$
①上述感觉动词与使役动词转换为被动结构时。其后的不定式一般需带to,如: Vl=!^T}l+
He was seen to come. |'@c ~yc
The boy was made to go to bed early. U*Q1(C
②在动词find与help之后,不定式可带to亦可不带to,如: mqw5\7s ?
He was surprised to find the sheep (to) break fence at this season.他发现羊在此季节越出栅栏,感到惊讶。 [[uKakp
3)在do nothing/anything/everything but(except)结构中。例如: h)S223[
Last night I did nothing but watch TV.昨天晚上,我除了看电视别的什么也没有干。 b|
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但是,如果谓语动词不是“do nothing,anything,everything”,那么but(except)所跟的不定式则仍须带。 B[XVTok
The doctor told him nothing but to stop smoking.医生除了让他戒烟,其它什么都没有说。 Hn~=O8/2
There was nothing for them to do but to remain silent.除了保持沉默以外,他们没有别有别的办法。 l#40VHa?S
(4)不定式与动名词的逻辑主语和分词独立结构 fP|rD[
1)不定式的逻辑主语为:for +名词(或代词宾格)+ 不定式。例如: pPI'0x
I found it impossible for him to do the job alone.我发现他—个人干这活是不可能的。 y"N7r1Pf
(注)在表示人物性格、特性等的形容词后面,常用of引出不定式的逻辑主语。例如: z4qw*. 5
It was wise of him to do that.他那样做是明智的。 rHS;wT
2)动名词的逻辑主语为;①人称代词的所有格+动名词;②名词‘s+动名词。例如: -e#~CE-
Tom insisted on my going with them.他坚持要我和他们一起去。 &