1、Unit 4 A good read,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: I dont know what to say.我不知道说什么。 Can you tell me how to use the camera?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 )
2、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: Can you tell me what I will do next? Can you tell me what to do next?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: He learnt ( how ) to swim last Sunday.上个星期天他学了游泳。
3、 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/have to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mustnt,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: We must keep our word.我们必须遵守诺言。 We mustnt waste our time.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neednt。例如: Must I come here tomorrow?我明天必须来这里吗? No,you neednt.不,
4、你不必。 ( 2 )意为“一定;必定是”,表示推断、推测。例如: You must be hungry.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dont 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: Its raining,and I have to stay at home.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: What
5、 does she have to do?她必须做什么?,.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.mustnt B.have to C.must D.neednt ( C )3.John left his h
6、omework at home,so he return home for it. A.has to B.must C.had to D.can,( D )4.There isnt any difference between the two dresses.I really dont 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.Its free. A.cant B.mustnt C.might not D.d
7、ont have to,.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 mustnt smoke ( smoke ) in the library. 5.We are talking about where to spend ( spend ) our
8、coming summer holiday.,.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 dont know where we can go on Sundays.( 改为同义句 ) Often we dont 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 dont have to go to school at weekends.,
