Must变为否定句，通常变为don't/doesn't have to 或者don't/doesn't need to或needn't do或can't.
因为must的否定形式mustn't意思已经变为'千万别'，不再表示不必须的意思了。。。
请采纳，谢谢~
含有情态动词must的句子变否定句怎么变
must 有非推测性用法和推测性用法两种情态意义，变否定句的方法不同。
▲非推测性用法的must表示义务，情态意义为“必须”。
He must finish his homework before bedtime. 他必须在上床前写完作业。
此用法的must两种否定形式：1. 结构上否定：在must改为must not或mustn't，情态意义为“不许”。
He mustn't finish his homework before bedtime. 不许他在上床前写完作业。
2. 意义上否定：将must改为need not或needn't，情态意义为“不必”。
He needn't finish his homework before bedtime. 他不必在上床前写完作业。
▲推测性用法的must表示必然，情态意义为“肯定”。
He must finish his homework before bedtime. 他肯定在上床前写完作业。
此用法的否定形式为can't，情态意义为“不可能”。
He can't finish his homework before bedtime. 他不可能在上床前写完作业。
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三十句不含be动词和情态动词句子变否定句一般疑问句
以下是used to构成疑问和否定的详细讲解和例句：used to作为情态动词，可直接在used后加not构成否定式，直接将used置于句首构成疑问式，但与一般的情态动词不同的，它也可像普通动词那样借助助动词did构成否定式和疑问式：He usedn't 〔didn't use〕 to come. 他过去不常来。
You used to go there, usedn't 〔didn't〕 you？ 你过去常到那儿去，是吗？Where did you use to live？ 你过去是住哪儿的？【注】在现代英语中，used to的否定式和疑问式通常借助助动词did构成（特别是在口语和非正式文体中），而直接将used作为助动词用通常被认为是非常正统或过时的用法。
然而有趣的是，有时还可见到以下这种混合形式：Did you used to be a teacher？ 你过去是当老师的吗？They didn't used to live here. 他们过去没住在这儿。
英语教师高中团队真诚解惑
句子中含有be动词和情态动词的句子,反义疑问句怎么变？
这样的说法很少见。
表示猜测预料的时候有五种通常表达法。
1. 有迹象预料推测be going to do疑问否定都用be be not2. 无迹象规律习惯性预料will do疑问否定都用will won't3. 80%以上很可能猜测must do疑问用can 否定用can't4. 50%左右猜测，有可能，may do或could do，疑问否定用could couldn't5. 30%也许大概猜测might do疑问否定用ought oughtn'the must be a teacher.Can he be a teacher?no, he can't be a teacher.he must be a teacher,can't he?他很可能是个教师，难道不可能吗？有时这样的问句常可根据内容来反问he must be a teacher, isn't he?他很可能是教师，难道不是吗？这种题的做法，只要牢记12个特殊助动词do be have can may must will shall used o
写出8句没有be动词和情态动词的肯定句变否定句。
还有2句有be动词...
1,I get up early. I don't get up early.2, I like her. I don't like her.3,I ate 3 eggs yesterday. I didn't eat 3 eggs yesterday.4. I bought a bag. I didn't buy a bag.5. He cried loudly. He didn't cry loudly.6. Mum goes to work at 8 :00. Mum don't go to work at 8:00.7. He told me something. He didn't tell me anything.8. I have a brother. I don't have a brother.9. He is 3 years old. He isn't 3 years old.10. I can write a letter. I can't write a letter.
含有情态动词的被动语态,如何变成被动语态的一般疑问句？
含有情态动词的被动语态，如何变成被动语态的一般疑问句？只要把情态动词调前就可以了。
The sentence can be translated this way.Can the sentence be translated this way?Your homework should be finished at once.Should my homework be finished at once?-Yes, it should./ No, it shouldn't. This work must be done at once.Must this work be done at once?-Yes, it must. / No, it needn't. 回答应保留原情态动词，但must表＂必须＂时，其否定回答应用needn't,need表＂必要＂时，其肯定回答应用must。
这和主动语态类似。
英语的否定句怎么写
1. 简单句中含有系动词be、情态动词和助动词时，变否定句时需在系动词be、情态动词和助动词后加not。
如： I am a teacher.→I am not a teacher. He can help me.→He can't help me. 2.简单句中谓语动词为行为动词时，要根据时态选用do的相应形式，把肯定句变为否定句。
如： The little girl wants to go there.→The little girl doesn't want to go there. He did his work yesterday.→ He didn't do his work yesterday. 3.祈使句变否定句时，一般在句首加Don't，但Let us或Let's开头的祈使句在 Let us或 Let's后加not即可。
如： Put them over there.→Don't put them over there. Let us go home.→Let us not go home. 4.主从复合句中，主句是I
如： I don't think chickens can swim .我认为鸡不会游泳。
5.“had better +动词原形”，变否定句时为“had better not +动词原形”。
如： You'd better go to school.→ You'd better not go to school. 6.动词不定式变否定式时，常在不定式to前加not。
如： The teacher tells me to do it.→ The teacher tells me not to do it. 7.使役动词和感官动词（make,let,hear,see,watch等）后接省略to的不定式，此种不定式变否定句时只需在省略to的动词原形前加not。
如： I saw her work.→I saw her not work. 8.特殊形式的否定句，有以下几种： （1）肯定句含有every-的合成词时，变否定句时改为no-。
如： Everything is ready.→Nothing is ready. 肯定句中含有always, usually和ever时，变否定句时改为never。
如： He is always late for school.→He is never late for school. 肯定句含有many,much时，变否定句时分别改为few,little。
如： Many students know him.→Few students know him. 肯定句中含有still时，变否定句时应改为no longer。
如： Tom is still in bed.→Tom is no longer in bed. 肯定句含有both, both...and,all时，变否定句时应改为never,neither...nor,none。
如： Both of us are students.→Neither of us is a student. 肯定句含有nearly, almost时，变否定句时应改为 hardly。
如： Lily nearly knows him .→Lily hardly knows him . 肯定句含有“形容词+ enough”时，变为否定句时应改为“too +形容词的反义词”。
如： He is short enough to reachit.He is too tall to reach it. 谓语动词是be,have（有）或谓语含有助动词、情态动词时，直接在这些词后加上否定词not。
如： She can swim.She can't swim. 谓语动词是行为动词时，要在该动词前加上do /does /did not，该词恢复原形。
如： He gets up early.He doesn't get up early. 既要否定谓语动词，又要变换句中的单词。
如： He can read and write.He can't read or write. 用含否定意义的词或词组取代肯定句中的某些词或词组。
如： I know both English and Chi- nese.I know neither English nor Chinese. 类似的有：ever /alwaysnever, somebodynobody,somethingnothing, everybody no one,almost hardly 9.祈使句的肯定式变否定式 （1）一般在动词前加上 don't。
如： Open the window .Don't open the window. 含有“Let's...”的祈使句，一般用“Let'snot...”的形式，美国人偶尔也用“Don'tlet's...”这一形式。
加强语气时使用“Let'sdon't...”这一形式。
如： Let's go there.Let's not go there. 10.复合句的肯定式变否定式 一般将主句变为否定式。
如：I saw her when I left .I didn't see her when I left.
写出5个句子中不含有be动词,情态动词,并变否定句,疑问句并做肯...
1.what. does he do . housework?No,he doesn't.2.Do they have .a libary?No,they don't3. Does Yang Ling have long hair....No,she doesn't.4.Does Amy like English?No,she doesn't.5.Do you often read books?No,l don't.
英语改为否定句？
画线提问一般是一个特殊疑问句 用特殊疑问词开头，结合生活实际，再会背单词就会了。
否定句一般是先看文中的单词 有行为动词（就是除了助动词和be动词外的单词），就加do或does肯定句就是对事物作出肯定判断的句子，否定句就是对事物作出否定判断的句子. 这两种句式在表达相同意思时，在语意上往往有轻重强弱的差别. 一般地说，同一句话，用否定句要比用肯定句语意要轻些，弱些. 例如： 1.这个道理容易明白. 2.这个道理不难明白. 这两句的意思差不多. 例1是肯定的说法，语气强些；例2是否定的说法，语气弱些. 否定句有两种类型： 一、一般否定句. 一般否定句只用一个否定词，常见的有“不”、“没”、“没有”等. 例如： 1.·激光不是一种普通的光. 2.··他没有来. 二、双重否定句. 双重否定句表示肯定的意思，它比肯定句语意要重些、强些. 例如： ···我不得不把这件事告诉了他. 例句用双重否定“不得不”表示没有任何理由隐瞒，比“我把这件事告诉了他”语意要强，语气也更加肯定. 下面看看肯定句与否定句的互换： 一、肯定句与一般否定句互换. 肯定句变换成一般否定句，只需用否定形式的同义短语去换原句的谓语中心词；否定句变换成肯定句，只需将原句中的否定形式短语用同义词换掉.