否定句的常见形式和用法

中学英语表达否定含义的句式形式多样,用法灵活.准确地掌握与否定相关的语句形式和用法,有助于提高英语阅读理解的准确性.本文就中学英语中否定句的常见形式和用法总结如下：
一、常见否定句：否定副词not, seldom, never, hardly, rarely, nowhere等与谓语动词连用.例如：
I’m afraid that I can not attend your party this weekend. 恐怕这个周末我不能参加你们的聚会.
I can hardly understand what he said just now. 我不能理解他刚才所说的话.
注意：这些否定副词用于句首时,主句要使用倒装语序.例如：
Seldom does he go to work late. 他很少上班迟到.
Nowhere else can you find such a beautiful sunset. 你在别的地方不能见到如此美丽的日落.
Never in my life have I heard such nonsense! 我这辈子从来没有听过这种废话!

二、否定祈使句：由“Don’t 或Never+ 动词原形”所构成.例如：
Don’t give up trying even though it is difficult to learn English! 
英语虽然难学,但千万别放弃尝试!
Do not cut down the tree that gives you shade. 切勿忘恩负义.
Never judge people by their appearance. 不可以貌取人.

三、全部否定：由“否定主语（否定代词或no+名词）+ 肯定谓语”所构成.例如：
Nothing is difficult if you put your heart into it. 世上无难事,只怕有心人.
None of us can speak French. 我们都不会讲法语.
No man is born wise. 人非生而知之.
注意：常用“neither/nor + 助动词/情态动词 + 主语”来表达“某人也不……”.例如：
Jim didn’t know her secret, neither/nor did Jack. 吉姆不知道她的秘密,杰克也不知道.
If you don’t accept his invitation, neither shall I. 如果你不接受他的邀请,我也不接受.

四、否定转移：常见的否定转移有两种情况.
1. 含有原因状语从句的主从复合句,形式上虽然否定主句的谓语,然而意义上则是否定该原因状语,译为“并不因为……而……”. 例如：
Galileo was not ready to accept it just because Aristotle had said so．
伽利略并不只是因为亚里斯多德说过某事如何如何,就轻易相信它.
The mountain is not valuable because it is high． 山不在高.
2. 当think, believe, suppose, expect, imagine等动词引导否定意义的宾语从句时,通常把从句中的not提前,把主句变成否定句,从句用肯定形式.例如：
We don’t believe that the news is true. 我们相信这个消息不是真的.
I don’t think that he is honest. 我认为他不诚实.
注意：（1）把这些发生否定转移的句子变为反意疑问句时,疑问部分应与宾语从句主谓部分构成反意疑问句.例如：
I don’t think that he is honest, is he? 我认为他不诚实.
（2）not 常用在I think, I believe, I expect, I suppose, I guess, I’m afraid之后,构成省略句.例如：
---Do you think it will be a fine day tomorrow? ---I’m afraid not. 
---你认为明天天气会好吗?---恐怕不是.
---Do you believe that Rocket will win the game? ---I believe not. (=I don’t believe so.)
---你相信火箭队会赢吗?---我看不会.

五、否定疑问句：常用来表示反问、惊讶、建议、赞叹等语气.例如：
Don’t you know these traffic rules? 难道你不知道这些交通规则吗?
Aren’t you supposed to be working? 你不是应该正在干活吗?
You look pale. Why don’t you have a rest? 你看起来脸色苍白,为什么不休息一会儿?
Isn’t it a lovely day? 天气多好啊!
注意：在回答否定疑问句时,要根据具体事实作答.例如：
---Didn’t you see the film Titanic yesterday? --- . I would like to have seen it.
A. Yes, I did B. No, I didn’t C. Yes, I didn’t D. No, I did
由于yes与肯定句连用,no与否定句连用,首先可排除C, D 两项.A, B 形式都正确,但从题目语境中最后一句话“我倒希望自己看了那部电影.”可知事实上我昨天没有看电影,故答案选B.如果把题干最后一句话改为“It’s very moving.”,则说明我昨天看过电影,正确答案就应该选A.这种“根据事实作答”在运用中很不容易掌握,大家应该仔细体会其用法；同时,这种应答方法也适合于对“前否后肯型”反意疑问句和否定祈使句的回答.例如：
---You haven’t been to Beijing, have you?--- . And I visited the Summer Palace.
A. Yes, I have B. Yes, I haven’t C. No, I have D. No, I haven’t
从答语提示可知事实上我去过北京,故答案选A.全句译为：“——你没有去过北京,是吗?——不,我去过.我还去参观过颐和园.”

六、非谓语动词的否定式：通常把not或never放在非谓语动词to do, doing, p.p的前面.例如：
I advised him not to smoke but he wouldn’t listen. 我劝他别抽烟,可他不愿意听.
Not having received a reply, she wrote him another letter. 
由于没有收到他的回信,她又给他写了一封信.
Not allowed to take part in the game, they felt very disappointed. 
因为不让他们参加比赛,他们感到非常失望.

七、双重否定句：由两个否定词搭配构成,表示一个较强的肯定语气.例如：
Without air or water, man can not live on the earth. 没有空气和水,人类是无法在地球上生存的.
Don’t try to operate this machine unless you know the rules for safety. 
如果不懂安全规则,千万别动这台机器.
It’s never too late to learn. 活到老,学到老.
He will not do it for nothing.�他不会无缘无故做这件事.
There is no success without hardships. 没有经历暴雨,那有彩虹.
If the world becomes less unfair, much of the poverty can be wiped out.
如果世界变得更加公平,就可以消除大部分贫穷.
He was nothing if not clever. 他很聪明.（“nothing if not”表示“极其”）

八、部分否定：通常由not 与表示整体意义的词（如：everyone, everything, all, each, always, entirely等）连用来表达.例如：
Not all the animals hibernate in winter. (或者：All the animals don’t hibernate in winter.) 
并非所有的动物冬天都要冬眠.
Everything on the Internet is not reliable. 网络上的东西并非都是可信的.
I’m not always at home on Sundays. 我星期天不一定总在家.
His attention was not entirely paid to his research. 他的注意力并未全部用在他的研究工作上.

九、含蓄否定：英语中有些句子虽然并不使用否定词,但也能表达否定意思.例如：
That is more than I can do. 我干不了那件事.
He is too young to carry so heavy a case. 他太小,搬不动这么重的箱子.
This is the last thing I would ever want to do. 这是我最不愿意做的事.
It is three years since he was a teacher. 他不当教师已经有三年时间了.（在“It is +时间段+ since …”结构中,从句谓语是延续性动词时表示否定意义.）
You could have done the job better if you had put more time into it. 如果你多花的时间,你的工作会做得更好.（工作做得并不好.用肯定形式的虚拟语气可以表示实际的否定意义.）

十、否定形式肯定意义： 英语中有些句子形式否定但却表达肯定意义,对其理解切不可望文生义.例如：
Isn’t this film moving? 这部电影难道不感人吗? （否定疑问句常表示肯定意义）
English is not too difficult to learn. 英语并不太难学. （双重否定句表示肯定意义.）
He is too ready to help others. 他总是乐于助人. (“too”修饰ready, glad, anxious, eager等词时相当于“very”）
You cannot be too careful to do your homework.（或者：You can never be careful enough to do your homework.）
做作业你越仔细越好(或者：无论怎样仔细也不过分).
He is too careful not to have noticed it. 
他那么小心,一定会注意到这一点的.(“too...not to do”表示“太……不会不……”)
There is nothing but sands left after the forest was destroyed. 
森林被毁之后,只剩下沙地.（“nothing but” 相当于“only”）
Jack didn’t understand why his mother was angry with him until she told him everything.
直到杰克的母亲把一切和盘托出,他才明白母亲为什么跟他生气.（“not...until”表示“直到……才”）
Hardly had I got to the station when it began to rain.
我刚到车站天就下雨了.（“hardly…when”表示“刚……就”,可以换成“no sooner…than”）
---Mr. Li is a good teacher.---I can’t agree more.
---李老师是个好老师.---我完全赞同.（否定词与比较级连用,强调所修饰的词的肯定意义.）
Why don’t you come and join us in the game? （ 或者：Why not come and join us in the game?）
你为什么不和我们一起玩游戏呢? (“Why don’t you…?”.或“Why not ...?”表示邀请、建议等肯定意义.)