Unit 4 A good read
单元语法专练
疑问词+动词不定式
1.动词不定式可以和疑问词what,how,when,where,which等连用(注意:疑问副词why后通常不接动词不定式),构成“疑问词+动词不定式”结构,在句子中作主语、宾语、宾语补足语等。常见和这种不定式短语结构连用的动词有tell,show,know,learn,forget等。例如:
Idon’tknowwhattosay.我不知道说什么。
Canyoutellmehowtousethecamera?你能告诉我怎样使用这部相机吗?
2.在运用“疑问词+动词不定式”结构时应注意以下几点:
(1)疑问代词往往是这一结构中不定式的宾语,因此,不定式中的动词应是及物动词或相当于及物动词的动词短语。而疑问副词在这一结构中只能作状语。
(2)作宾语用的带疑问词的不定式短语相当于一个宾语从句。可以通过用“疑问词+不定式”结构把一个复合句转换成简单句。例如:
CanyoutellmewhatIwilldonext?
→Canyoutellmewhattodonext?你能告诉我接下来做什么吗?
(3)某些动词后面的不定式短语省去疑问词并不会造成意义上的差异。例如:
Helearnt(how)toswimlastSunday.上个星期天他学了游泳。
注意:在动词know后面的不定式一定要有疑问词,绝对不能省去。
must/haveto的用法
1.must表示“必须”,侧重于说话者的主观看法,认为有必要或有义务去做某事;其否定形式mustn’t,表示“禁止;不允许”。具体用法如下:
(1)意为“必须,应当”,表示义务、命令或必要。例如:
Wemustkeepourword.我们必须遵守诺言。
Wemustn’twasteourtime.我们不能浪费时间。
由must引起的一般疑问句的否定回答要用needn’t。例如:
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—MustIcomeheretomorrow?我明天必须来这里吗?
—No,youneedn’t.不,你不必。
(2)意为“一定;必定是”,表示推断、推测。例如:
Youmustbehungry.你一定饿了吧。
2.have to“必须;不得不”,有人称、数和多种时态的变化。侧重于客观需要,含有不得不或被迫之意。其否定形式don’t have to表示“没必要”。具体用法如下:
(1) have to强调由于客观条件需要而不得不做某事。例如:
It’sraining,andIhavetostayathome.外面在下雨,我不得不待在家里。
(2) have to不能直接构成否定句或疑问句,需要借助于助动词。以一般现在时为例,需要借助于do或does。例如:
Whatdoesshehavetodo?她必须做什么?
Ⅰ.单项填空
(B)1.Excuse me,could you please tell me my car?
A.why to stop B.where to park
C.where can I park D.how can I park
(A)2.—What should we do to protect the fish in the river?
—We throw rubbish into the river.
A.mustn’t B.have to
C.must D.needn’t
(C)3.John left his homework at home,so he return home for it.
A.has to B.must
C.had to D.can
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(D)4.There isn’t any difference between the two dresses.I really don’t know .
A.to choose what B.to choose which
C.what to choose D.which to choose
(D)5.We pay to get into the concert.It’s free.
A.can’t B.mustn’t
C.might not D.don’t have to
Ⅱ.根据句意用所给词的适当形式填空
1.Mr Green showed us what to do (do) first.
2.Li Feng did not know who to talk (talk) to about this book.
3.Students do not have to go (go) to school at weekends.
4.Everyone mustn’t smoke (smoke) in the library.
5.We are talking about where to spend (spend) our coming summer holiday.
Ⅲ.按要求完成句子,每空一词
1.Simon forgets when he will meet his friend.(改为同义句)
Simon forgets when to meet his friend.
2.Often we don’t know where we can go on Sundays.(改为同义句)
Often we don’t know where to go on Sundays.
3.The Greens are discussing which colour they will use to paint the walls.(改为同义句)
The Greens are discussing which colour to use to paint the walls.
4.We have to go to school at weekends.(改为否定句)
We don’t have to go to school at weekends.
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