初中英語語法一般現在時講解：否定句的結構

一般現在時的結構是由動詞原形構成的。根據人稱的變化，謂語動詞有單、複數的變化。它可以表示經常的、現在的、過去的、將來的動作。今天小編給大家推薦的一般現在時講解：否定句的結構一文。希望對大家有所幫助。

一般現在時的否定句

一、一般現在時變否定句的規則.

一)、主語+be動詞

含有 am is are 的句子,變否定句時,只需在am is are 後加not.

【例】This is a book. 否定句 This is not a book .

I am a teacher . 否定句I am not a teacher .

These are pens . 否定句These are not pens .

二)、主語+實義動詞

含有實義動詞的句子，變否定句分兩種。

1、如果主語是第三人稱單數時，要在實義動詞前加doesn't,後面的動詞用原形。

【例】He eats an apple. 否定句 He doesn't eat an apple.

Jim does his homework. 否定句 Jim doesn't do his homework.

Marry goes to school. 否定句Marry doesn't go to school.

2、 如果主語不是第三人稱單數時，只需在實義動詞前加don't.

【例】I teach English. 否定句 I don't teach English.

三)、主語+情態動詞

含有情態動詞的句子,變否定句時, 只需在情態動詞後加not.

【例】 I can dance. 否定句 I can not dance. 或 I can't dance.

They can speak English. 否定句 They can not speak English. 或They can't speak English.

【注意】He must be on the playground. He can not be on the playground. 析：當must be用來表示推測，有“一定”的含義時， 否定式要用can not.

You must say something at the mecting.否定句 You needn’t say anything at the mecting.

析：當“must+行為動詞”用來表示“必須”的含義時，其否定式可用needn’t 或mustn't表示“不需要”，“不必”， 語氣委婉，must not表示“禁止”，“千萬別”語氣生硬。

You may come in now. You mustn't come in now.

析：may作為情態動詞表示“可以”時， 其否定式用must not,而不用may not.

四)、注意

1、含有have和has的句子變成否定句

have和has，變否定句不能在have和has後加not，則需要助動詞來幫助解決。

have→do not have或don’t have

has→does

not have或doesn’t have (has要變成have)

【例】I have a pen. 否定句I don’t have a pen。

My father has a watch. 否定句 My father doesn't have a watch.

2、見到some 變否定句時,要換成any.

【例】I eat some apples. 否定句 I don't eat any apples.

He has some books. 否定句 He doesn't have any books.

He does his home work. 否定句 He doesn't do his home work.

3、見到and 變否定句時,要換成or.

【例】There is some air and water on the moon.

否定句 There isn't any air or water on the moon.

He has some brothers and sisters.

否定句 He hasn't any brothers or sisters.

He eats apples and oranges.

否定句He doesn’t eat apples or oranges.

4、見到too和also變否定句時,要換成either.

too和also用於肯定句中時，否定句中用either替換。

【例】Tom goes to school too.

否定句 Tom doesn’t go to school either.

5、a lot of (=lots of)變為many或much。

【例】They have a lot of friends.(可數名詞)

否定句They don't have many friends.

There is lots of orange in the bottle.(不可數名詞)

否定句There isn't much orange in the bottle.

6、見到already變否定句時,要換成yet。

【例】He has had supper already.

否定句 He hasn’t had supper yet.
以上就是小編為大家整理的一般現在時的否定句結構，掌握基本結構之後做題就很順利了，希望各位同學學完此結構之後多加練習，鞏固自己的學習。