肯定句/否定句/疑问句之变形技巧一、肯定句改否定句1、be动词后加not，诸如：is not(isn't)，are not(aren't)，was not(wasn't)，were not(weren't)，am not（无缩写）。
◆He is a student. 他是一个学生。
--- He is not a student. 他不是一个学生。
◆They were watching TV then. 那时他们正在看电视。
--- They weren't watching TV then. 那时他们没在看电视。
2、情态动词等后加not，诸如：can not(can't)，will not(won't)，should not(shouldn't)，must not(mustn't)，need(needn't)等。
◆She can take care of herself. 她能照顾好她自己。
--- She can not(can't) take care of herself. 她不能照顾好她自己。
◆You should go home. 你应该回家。
--- You shouldn't go home. 你不应该回家。
3、若无法找到be动词或情态动词，就在已有动词前额外加助动词否定形式：don't/doesn't/didn't，同时将动词变原形。
◆She likes the room. 她喜欢这房间。
--- She doesn't like the room. 她不喜欢这房间。
◆We did our homework yesterday. 我们昨天做了作业。
--- We didn't do our homework yesterday. 我们昨天没有做作业。
注：句中若有some ，须将其改成any。
◆I want some books. 我想要一些书。
--- I don't want any books. 我不想要任何书。
◆There is some water in the cup. 杯子里有一些水。
--- There isn't any water in the cup. 杯子里没有水了。
二、肯定句改一般疑问句（三步法）#1：把be动词（am/is/are...）或情态动词（can/will...）放在句首。
若句中没有上述动词，就把助动词放在句首（do/does/did），同时将动词变原形。
#2：剩余部分照写。
注：some须改成any，I或we均改成you，my或our均改成your。
#3：句点改成问号。
◆I can swim. 我会游泳。
Can you swim? 你会游泳吗？◆There is some water in the cup. 杯子里有一些水。
Is there any water in the cup. 杯子里有水吗？◆I studied hard. 我学习认真。
Did you study hard? 你学习认真吗？三、肯定句改特殊疑问句（四步法）#1：在一般疑问句基础上，句首添加一个疑问词即可，但应根据划线部分选用适配的疑问词。
#2：把be动词或情态动词等放在疑问词后面，若句中没有上述动词，就用助动词替代（do/does/did）。
注：Whose（谁的）和How many（多少）两词除外，须紧跟物品，再写be动词或情态动词等。
#3：划线部分去掉后剩下的内容照写。
注：some须改成any，I或we均改成you，my或our均改成your。
#4：句点改成问号。
★考试中出现频率颇高的20个特殊疑问句1、划线部分是“事或物”，疑问词用What。
◆This is a book. 这是一本书。
--- What is this? 这是什么？◆I often play football on Saturdays. 我经常在周六踢足球。
--- What do you often do on Saturdays? 你经常在周六做什么？2、划线部分是“职业”，疑问词用What。
◆Mike is a worker. 迈克是一个工人。
--- What is Mike? 迈克是做什么的？◆I'm a policeman. 我是一名警察。
--- What do you do? 你是做什么的？3、划线部分为“人名”，疑问词用What。
My name is Amy. 我叫艾米。
--- What's your name? 你叫什么名字？4、划线部分为“天气”，疑问词用What或How。
It's cold and windy in winter. 冬天很冷，而且风大。
--- What's the weather like in winter? 冬天的天气怎么样？（= How is the weather in winter in Beijing?）5、划线部分是“颜色”，疑问词用What colour。
My hat is blue. 我的帽子是蓝色的。
--- What colour is your hat？你的帽子是什么颜色？6、划线部分是“星期几”，疑问词用What day。
It's Monday. 今天星期一。
--- What day is today? 今天星期几？7、划线部分是“时间”，疑问词用What time或When。
◆It's seven twenty. 现在七点二十。
--- What time is it? 现在几点了？◆I usually get up at six. 我通常六点起床。
--- When do you usually get up? 你通常什么时候起床？8、划线部分是“人”，疑问词用Who。
He is my brother. 他是我哥哥。
--- Who is he? 他是谁？9、划线部分是“形容词性物主代词或名词性物主代词”，疑问词用Whose。
This is my bag.（= This bag is mine.）这是我的包。
--- Whose bag is this? 这是谁的包？10、划线部分是“原因”，疑问词用Why。
He isn't at school because he is ill. 他因为生病而没去学校。
--- Why isn't he at school? 他为什么不在学校？11、划线部分是“地点”，疑问词用Where。
The box is on the desk. 这盒子在桌上。
--- Where is the box? 盒子在哪里？12、划线部分是“方式”，疑问词用How。
She usually goes to school by bike. 她通常骑自行车去上学。
--- How does she go to school? 她是怎样去上学的？13、划线部分是“年龄”，疑问词用How old。
I'm twelve. 我十二岁。
--- How old are you? 你多大了？14、划线部分是“数量”，疑问词用How many或How much。
◆I can see five kites. 我能看到五只风筝。
--- How many kites can you see? 你能看见几只风筝？◆There is some milk in the glass. 杯里有一些牛奶。
--- How much milk is there in the glass? 杯里有多少牛奶？15、划线部分是“多少钱”，疑问词用How much。
This pen is nine yuan. 这笔价格九元。
--- How much is this pen? 这笔多少钱？16、划线部分是“距离”，疑问词用How far。
It's ten minutes' walk. 步行十分钟的路程。
--- How far is it? 到那有多远？17、划线部分是“长度”，疑问句用How long。
The river is about 500 km. 这条河长约500千米。
--- How long is the river? 这条河有多长？18、划线部分是“频率”，疑问词用How often。
I watch TV twice a week. 我一星期看两次电视。
--- How often do you watch TV? 你每多久看一次电视？19、划线部分是“时长”，疑问词用How long或How soon。
◆I will stay there two weeks. 我将会在那儿呆两个星期。
--- How long will you stay there? 你将在那儿呆多久？◆He will come back in an hour. 他一小时后回来。
--- How soon will he come back? 他过多久回来？20、划线部分是“次数”，疑问词用How many times。
He called me twice yesterday. 他昨天给我打了两次电话。
--- How many times did he call you yesterday? 他昨天给你打了几次电话？。