专题:
一般否定句：I don't know this. No news is good news.特指否定：He went to his office, not to see him. I am sorry for not coming on time.部分否定 ：否定词加表示全体的词：I don't know all of them.
否定句例子
（1）一般否定句
I don't know this. No news is good news.
There is no person（smoking）/not a person/not any person（smoking）in the house.
（2）特指否定
He went to his office, not to see him.
I am sorry for not coming on time.
I don't think / believe/suppose / feel / imagine you are right.
（3）部分否定
All the answers are not right
All is not gold that glitters
I don't know all of them.
I can't see everybody/everything.
Both of them are not right.
否定句改变方法
表示某一否定意思。句中一定有not。
有三种可能:be动词(am、is、are、was、were)+not、情态动词(can、must、should)+not、助动词(do、does、did)+not
1.看句中有无be动词，如有,直接在be动词后+not。
2.看句中有无情态动词，如有,直接在情态动词后+not
3.如上述二者都没有,就应用助动词+not
分四个步骤:
(1)肯定陈述句中本来是没有助动词的,要加上去,位置在主语(某人或某物)后,动词前。
(2)确定助动词用do、does还是did,根据句中动词,动词是原形的助动词就用do,动词是第三人称单数的助动词就用does,动词用过去式的助动词就有did。
(3)在助动词后加not。
(4)原句中动词假如发生变化就要恢复成原形。