一般现在时变否定句的规则

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 后力口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.

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.

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 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.