一般现在时变否定句的规则.(a) 含有am is are 的句子,变否定句时,只需在am is are 后加not.例1 This is a book.否定句This is not a book .例2 I am a teacher .否定句I am not a teacher .例3 These are pens .否定句These are not pens .(b) 含有实义动词的句子，变否定句分两步。

（1）如果主语是第三人称单数时，要在实义动词前加doesn't,后面的动词用原形。

例1 He eats an apple.否定句He doesn't eat an apple.例2 Jim does his homework.否定句Jim doesn't do his homework.例3 Marry goes to school.否定句Marry doesn't go to school.(2) 如果主语不是第三人称单数时，只需在实义动词前加don't.例1 I teach English.否定句I don't teach English.例2 They go to school.否定句They don't go to school.例3 We sing a song.否定句We don't sing a song.(c) 含有情态动词的句子,变否定句时, 只需在情态动词后加not.例1 I can dance.否定句I can not dance.或I can't dance.例2 They can speak English.否定句 They can not speak English.或They can't speak English.例3 He must go home.否定句He must not go home.或He mustn't go home.例4 He must be on the playground.He can not be on the playground.析：当must be用来表示推测，有“一定”的含义时，否定式要用can not.例5 You must say something at the mecting.You needn’t say anything at the mecting.析：当“must+行为动词”用来表示“必须”的含义时，其否定式可用needn’t 或mustn't表示“不需要”，“不必”，语气委婉，must not表示“禁止”，“千万别”语气生硬。

例6 You may come in now.You mustn't come in now.析：may作为情态动词表示“可以”时，其否定式用must not,而不用may not.例7 He may watch TV .He mustn't watch TV.注意:(1) 见到some 变否定句时,要换成any.例1 I eat some apples.否定句I don't eat any apples.例2 He has some books.否定句He doesn't have any books.例3 He does his home work.否定句He doesn't do his home work.(2) 见到and 变否定句时,要换成or.例1 There is some air and water on the moon.否定句There isn't any air or water on the moon.例2 He has some brothers and sisters.否定句He hasn't any brothers or sisters.例3 He eats apples and oranges.否定句He doesn’t eat apples or oranges.(3) 见到too和also变否定句时,要换成either.例1Tom goes to school too.否定句Tom doesn’t go to school either.too和also用于肯定句中时，否定句中用either替换。

（4 见到already变否定句时,要换成yet。

例1 He has had supper already.He hasn’t had supper yet.随着对谓语动词的否定，某些副词也要作相应的变动。

一般现在时精炼一将下列句子变否定句。

例1 I am a boy.例2 You are a girl.例3 He is a teacher.例4 Jim is English.例5 These are bikes.例6 Those are maps.例7 They are buses.例8 We are Chinese.二将下列句子变否定句。

例1 I’m a boy.例2 You’re a girl.例3 He’s a teacher.例4 It’s a pen.例5 These are some bikes.例6 Those are maps and pencils. 例7 They’re some buses and cars.例8 She is your teacher.三将下列句子变疑问句。

例1 I am a boy.例2 You are a girl.例3 He is my teacher.例4 Jim is our English.例5 These are some bikes.例6 Those are my maps.例7 They are some buses.例8 We are Chinese.四将下列句子变成疑问句。

例1 I’m a boy.例2 You’re a girl.例3 He’s my teacher.例4 It’s a pen.例5 These are some bikes.例6 Those are maps and pencils. 例7 They’re some buses and cars.例8 She is your teacher.五将下列句子变否定句。

例1 I teach English.例2 They go to school.例3 We sing a song.例4 He spells it.例5 She goes to school.例6 He does his homework..例7 They do their homework.例8 I do my homework.六将下列句子变否定句。

例1 He teaches my English.例2 They speak English and French.例3 We eat some apples.例4 Jim spells it.例5 She goes to our school.例6 He does some homework..例7 They do their homework.例8 We do some homework.七将下列句子变疑问句。

例1 I teach English.例2 They go to school.例3 We sing a song.例4 He spells it.例5 She goes to school.例6 He does his homework..例7 They does their homework.例8 I do my homework.八将下列句子变疑问句。

例1 He teaches my English.例2 They speak English and French.例3 We eat some apples.例4 Jim spells it.例5 She goes to our school.例6 He does some homework..例7 They do their homework.例8 We do some homework.九将下列句子变否定句。

例1 I can dance.例2 They can speak English.例3He must go home.例4 He must be on the playground. 例5 You must say something at the mecting.例6 You may come in now.例7 He may watch TV .例8 We need speak English.十将下列句子变否定句。

例1 I can dance and sing.例2 They can speak some English.例3You must go home.例4 They must be on the playground. 例5He must say something at the mecting.例6 Jim may come in now.例7 They may watch TV .例8 We need speak English and English.十一将下列句子变疑问句。

例1 I can dance.例2 They can speak English.例3He must go home.例4 He must be on the playground. 例5 You must say something at the mecting.例6 You may come in now.例7 He may watch TV .例8 We need speak English.十二将下列句子疑问定句。

例1 I can dance and sing.例2 They can speak some English.例3You must go home.例4 They must be on the playground.例5He must say something at the mecting.例6 You may come in now.例7 They may watch TV .例8 We need speak English and English.十三写出下列动词的第三人称单数形式。

1 go2 spell3 speak 4like 5teach6 Be7 are8 study9 have 10 do十四将下列名词变成复数。