??含有否定词not，no，nothing ，never等或表示部分否定的词hardly，barely等的句子被称为否定句。英语的否定句表现形式多种多样，应用十分广泛，但形式上的否定并不等于意义上的否定，在很多情况下，形式上的否定句表达的却是肯定的含义，需注意这类句子的理解和译法。

??1．not ．．．until／till 直到……才，只有……才
??People do not know the blessing of health until they loseit．
??人们直到失去了健康才知道健康的可贵。
??You can not learn anything till you rid yourself of complacency．
??只有去掉自满，你才能真正学点东西。
??It was not until a Saturday afternoon in May that Margaret could arrange for me to? meet her elder sister．
??直到五月的一个星期六下午，玛格丽特才安排我与她姐姐见面。

??2．not．．．long before 很快就，不久就
??It wasn't long before he told us about this affair．不久他就告诉了我们这件事。
??It won't be long before we finish the work．我们很快就会干完这活儿。
??It will not be long before they come back．他们很快就会回来。

??3．cannot．．．too．．．无论怎样……也不会过分，越……越好
??This can't be stressed too strongly．这一点怎么强调也不过分。
??One can never be too careful in this kind of work．干这种工作越仔细越好。
??We can hardly praise his achievem ent too much．对他的成绩我们怎么赞扬也不过分。

??4．too．．．not to．．．太……一定会／不会不
??He is too wise not to see the reason．他太精明了，一定会看出其中的原因。
??He is too smart not to see your point．他很聪明，不会不明白你的意思。
?
??5．no sooner．．．than ，hardly／scarcely．．．when 刚……就……
??No sooner had he entered the office than the telephone rang．
??他刚进办公室，电话铃就响了。
??We had hardly got on the train when it began to pull out．
??我们刚上车，火车就开了。

??6．not／no／never．．．without．．．否定词与具有否定意义的介词连用，构成双重否定，表达肯定意义。
??There is no fire without some smoke．有火就有烟。
??I never knew him do anything without a very good reason．
??我知道，他做什么事都有充分的理由。
??At the beginning of his learning English he could not speak without making mistakes．
??在开始学英语时，他一讲话就出错。

??7．but常用于否定句中，构成较为固定的句型，表达肯定的含义，常见的有：nothing／none but（只有，只有……才），never（not）．．．but（每当……，总是……），no（nobody）．．．but（都会……；没有……不），can not but／can not help（but）（一定，只好，不能不），cannot choose but（只能）等。
??The old society gave the laboring people nothing but misery．
??旧社会给劳动人民带来的只有痛苦。
??I never go past my old school but I think of Mr Wilkins，the headmaster．
??每当经过我的母校，我总是想起校长威尔金斯先生。
??None but a fool would do such a thing．只有傻瓜才会做这种事情。
??Nobody reads the book but will be moved．这本书谁读了都会感动。
??This can't but be the place he mentioned．这一定是他提到的那个地方。
??The policeman could not help but let him go．警察只好让他走。

??8．否定词与比较级连用，表示肯定含义，意为"最"，"极其"。
??I couldn't feel better．我感觉好极了。
??To her，nothing is more humiliating than being laughed at by others．
??被人嘲笑是最另她感到屈辱的事情。
??Nobody is more selfish than her in the class．她是班里最自私的了。

??9．other than，else than，short of， otherwise than与否定词连用的一些结构具有肯定的含?义，常见的有：no／none other than（正是），nothing short of（简直是，就是），nothing else than（完全是），no／not．．．otherwise than（只是，只能）等。
??His failure was due to nothing else than his own carelessness．
??他的失败完全是由于他自己的粗心大意。
??The setting up of this plant in three months is nothing short of a miracle．
??三个月就建成了这座工厂，简直是个奇迹。
??The door cannot be opened otherwise than with a key．这门只能用钥匙才能打开。
??Don't you know this comrade？He is none other than our factory director．
??你不认识这位同志？他就是我们厂厂长。

??10．not a little，no little，not a few，no few，no common等表达的是肯定的含义，具有 much，many之意。
??The teacher has not a little experience．这位教师有着丰富的经验。
??He knows no few famous singers．他认识许多著名的歌手。