一般現(xiàn)在時(shí)講解：否定句的結(jié)構(gòu)

　　一般現(xiàn)在時(shí)的結(jié)構(gòu)是由動(dòng)詞原形構(gòu)成的。根據(jù)人稱的變化，謂語(yǔ)動(dòng)詞有單、復(fù)數(shù)的變化。它可以表示經(jīng)常的、現(xiàn)在的、過(guò)去的、將來(lái)的動(dòng)作。今天小編給大家推薦的一般現(xiàn)在時(shí)講解：否定句的結(jié)構(gòu)一文。希望對(duì)大家有所幫助。

　　一般現(xiàn)在時(shí)的否定句

　　一、一般現(xiàn)在時(shí)變否定句的規(guī)則.

　　一)、主語(yǔ)+be動(dòng)詞

　　含有 am is are 的句子,變否定句時(shí),只需在am is are 后加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(yǔ)+實(shí)義動(dòng)詞

　　含有實(shí)義動(dòng)詞的句子，變否定句分兩種。

　　1、如果主語(yǔ)是第三人稱單數(shù)時(shí)，要在實(shí)義動(dòng)詞前加doesn't,后面的動(dòng)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(yǔ)不是第三人稱單數(shù)時(shí)，只需在實(shí)義動(dòng)詞前加don't.

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

　　三)、主語(yǔ)+情態(tài)動(dòng)詞

　　含有情態(tài)動(dòng)詞的句子,變否定句時(shí), 只需在情態(tài)動(dòng)詞后加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(dāng)must be用來(lái)表示推測(cè)，有“一定”的含義時(shí)， 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(dāng)“must+行為動(dòng)詞”用來(lái)表示“必須”的含義時(shí)，其否定式可用needn’t 或mustn't表示“不需要”，“不必”， 語(yǔ)氣委婉，must not表示“禁止”，“千萬(wàn)別”語(yǔ)氣生硬。

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

　　析：may作為情態(tài)動(dòng)詞表示“可以”時(shí)， 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后加not，則需要助動(dòng)詞來(lái)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(jiàn)到some 變否定句時(shí),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(jiàn)到and 變否定句時(shí),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(jiàn)到too和also變否定句時(shí),要換成either.

　　too和also用于肯定句中時(shí)，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?yōu)閙any或much。

　　【例】They have a lot of friends.(可數(shù)名詞)

　　否定句They don't have many friends.

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

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

　　6、見(jiàn)到already變否定句時(shí),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(xiàn)在時(shí)的否定句結(jié)構(gòu)，掌握基本結(jié)構(gòu)之后做題就很順利了，希望各位同學(xué)學(xué)完此結(jié)構(gòu)之后多加練習(xí)，鞏固自己的學(xué)習(xí)。