1、.匕一、動詞be的否定式動詞be根據(jù)不同的人稱和時態(tài)可以有 am, is, are, was, were 等不同形式，可 用作連系動詞（表示“是、“在”等）和助動詞（用于構成進行時態(tài)和被動語態(tài)等）， 但不管何種情況，構成否定式時，一律在其后加 not。 I mold, but you re young. T mnot old, but you re not young. He was reading and I was writing.fHe was not reading and I was notwriting.二、動詞have的否定式動詞have根據(jù)不同的人稱和時態(tài)可以有 have, h

2、as, had等形式，可以用作實意 動詞和助動詞，分以下情況討論。1.用作實意動詞表示狀態(tài)，如表示擁有、患病或用于 have to表示“必須”等， 在構成否定式時可以直接在其后加 not,也可根據(jù)情況在其前使用dont, doesn t , didn t。 He has a car. fHe hasn t a car. / He doesn t have a car. He had somedictionaries. fHe hadn t any dictionaries. / He didn t have any dictionaries. You have to go with him.

3、fYou haven t to go with him. / You don t have to go with him.【注】have to構成否定式時以在其前加don t等較為常見。2.用作實意動詞表示動作，如表示“吃（二eat） ”、“喝（二drink） ”、“拿（二take） ”、 “收到（=receive） ”、“度過（二spend） ”等，構成否定式時不能直接在其后加 not, 而應根據(jù)情況在其前使用don t, doesn t, didn t。 He had some cake for breakfast. f He didn t have any cake for breakf

4、ast. We had a good holiday.fWe didn t have a good holiday.3.用作助動詞構成完成時態(tài)，其否定式只能在其后加not。 I have read the book. fI have not read the book. He had left when I arrived. fHe hadn t left when I arrived.三、情態(tài)動詞的否定式情態(tài)動詞的否定式一般在其后加not構成。 I can finish the work in an hour.hour.f I can t finish the work in an You

5、must go with us. fYou mustn t go with us. We should help them. fWe shouldn t help them.四、實意動詞的否定式一般實意動詞的否定式，通常應根據(jù)不同時態(tài)和人稱在實意動詞之前加don t,doesn t, didn t 等。 He works in a bank. fHe doesn t work in a bank. We often hear from her.fWe don t often hear from her. I met her at the station.T didn t meet her at

6、 the station.汪忠：加上does not或did not改為否定句以后，要把原句的動詞改為原形動詞，特 別是行為動詞do的第三人稱單數(shù)does和過去時did ,在主語后面加上doesnt 或didnt以后，千萬要注意把句中的 does或did改為do。五、祈使句的否定結構為：dont十原形動詞改為否定何時，要在句首加上 dont ,其它不變，即：Look out of the window . fDont 100k out of the window .六、當陳述句中含有 something這個詞時把句子改為否定句有兩種方法：其一，在句中相應位置加not,再把something改成

7、 anything ； 其二，直接把 something 改為 nothing 即可。 There is something wrong with the radio .把這個句子改為否定句有兩種方法：具先把 not力口在is 后面，再把 something 改為 anything 即：There is not anything wrong with the radio .其二把 something 直接改為 nothing , 即：There is nothing wrong with the radio . I have something important to tell you .把

8、這個句子變成否定句有兩種方法：其中一種方法是先把 not加在have后面，再把something變成anything ,即：I have not anything important to tell you.第二種方法是直接把 something 改為 nothing ,即：I have nothing importantto tell you七、當陳述句是一個主從復合句而主句的謂語動詞是think或believe等時，把這種句子改為否定句，往往是否 定think或believe等而不否定后面從句中的謂語動詞，盡管意思是否定從何的 謂語動詞。 I think he will be back s

9、oon這個復合旬中主句的謂語動詞是think ,所以在改為否定何時要在think前面加 上 dont ,即：I dont think he will be back soon .漢語意思：我認為他不 會很快回來。八、某些特殊句型改為否定句時，有不同的方法：1 .在陳述句中含有had better時，要把not加在better后面，動詞原形前面。 You had better go with us把這個句子改為否定何，要把not加在better 之后，g o之前，即：You had better not go with us . 千萬不要改成： You had not better to go

10、with us . 或 You had better dont go with us .因為，要否定的是后面的動詞不定式短語。同 時，had better后面要用動詞原形（不帶to ）2 .當陳述句中含有both +名詞或者both of +名詞作主語時，改為否定何時則 用neither代替both ,并且要注意謂語動詞數(shù)的變化。 Both of them work in the school library .句子含有both ,改為否定何時用neither代替both ,同時謂語動詞 work改為 works , 即： Neither of them works in the school

11、 library. Both answers are right .把這個句子改為否定句，用 neither代替both，謂語動詞are改為is ,即： Neither answer is right .3 .句中含有both . . and的肯定旬改為否定何時用 neither . nor改寫，同 時neither . nor還可以把兩個簡單句的否定形式連成一個句子。 Both Mary and Joan are students .把這個句子改為否定何時，通常用 Neither . . nor代替Both. and,同時把 are 改為 is , students 改為 a student

12、 即：Neither Mary nor Joan is a student .4. neither . . nor連接兩個主語時，謂語動詞決定于nor后面的名詞或代詞的 單復數(shù)形式。 This book is both interesting and instructive把這個句子改為否定句，用 neither . nor代替both. and,因為連接部分在句中作表語，所以謂語動詞不變，即： This book is neither interesting nor instructive . I dont see that film . He doesnt see it either .這

13、兩個否定句可以用neither . . nor連成一個句子，謂語動詞改為肯定式 see, 人稱和數(shù)由nor后面的he決定，即：Neither he nor I see that film或者把I和he交換.即：Neither I nor he sees that film .這說明謂語的人稱 和數(shù)由nor后面的靠近謂語的人稱和數(shù)決定。在把肯定句改為否定何時，注意把 句中的some, 改成any。鞏固練習：將下列句子改為否定句1. We do morning exercises every dayWe morning exercises every day2. All of us can swi

14、mcan swimJoan I in Class One4. There is something wrong with my bike There wrong with my bike5. You may stay here before I come back .You here before I come back .6. Read the text after me .the text after me .7. Li Lei needs some help with his English .Li Lei help with his English.8. He said he woul

15、d g o to Beijing the next week .Hego to Beijing thenext week .9. The bike has already been m ended .The bike mended10. I think it is going to rain tomorrow.I going to rain tomorrow.Key:1 . dont do 2 . None of us 3 . Neither ; nor; am 4. is nothing5. mustnt stay 6. Dont read 7. doesnt need any 8. didnt say he would 9 . h