英语中有些句子形式上是否定的，但是内容含义上却是肯定的。 一、 cannot wait 后跟不定式， 意为“急于做”，表示强调的肯定 I couldn’t wait to see her. 我渴望见到她。 I cannot wait to read the book. 我非常渴望读到这本书。 二、 cannot/couldn’t＋too意为 “越„„越„„ ，非常，无论怎样„„也不过分” 在此结构中，cannot 也可改用can hardly，scarcely，never，impossible；too也可改用over，enough等。 A man can never have too many friends. 朋友越多越好。 He cannot see you quickly enough. 他想很快见到你。 三、 not„ until/ till 意为 “直到„„的时候才” People take no thought of the value of time until they lose it.人们失去时间后才知道时间的价值 It was not until the next day that I knew that truth. 直到第二天我才知道真相。 He did not go to bed until his mother came back. 直到他母亲回来他才睡觉。 四、否定词＋but 1、not(no)„but There is no man but has his faults. 人皆有过。 No one believes but she will succeed. 人们相信他会成功。 There is no one but knows him. 人人都认识他。 2、 never (not)„but (that) 意为 “每当„„, 总是„„, 没有哪次不是„„”。 I never see you but I think of my mother. 每当看见你时,我总是想起我的母亲。 He will not be angry but that he is offended. 人们惹了他他才会生气。 3、 nothing but /none but 意为 “仅仅,只,只有„„才”。 We can see nothing but water. 我们只能看见水。 None but me knew what happened. 只有我知道发生了什么事情。 He chose none but the best. 他只选最好的。 五、 not long before 意为“不久„„就„„” It was not long before he appeared. 他不久就出现了。 六、 否定词＋without 意为 “ 每 „„ 必” What appeared to me wonderful was that none of the ants came home without bringing something. 使我感到惊奇的是每只蚂蚁回来都带回一些东西。 There is no smoke without fire. 有烟必有火。 七、 no (none) other than意为 “仅仅,完全” She is none other than my teacher. 她正是我的老师。 The letter was written by none other than Mary. 写这封信的正是玛莉。 八、 too + 形容词 / 副词 + not ＋ 不定式 “非常„„必定能，太„„不会不” 1. 本句型是对too „ to 的否定，表示肯定意思。 His speech was too good not to stir the audience. 他的演讲太好了，不会不使观众轰动。 He is too foolish not to say it. 他那么傻，不会不把这事说出来。 2. 若 把否定词放到前面not too „ to 表示这并不太„„所以能。 He is not too old to do it. 他做这件事，年龄并不老。 3. never too „ to (永不/决不„„)。 It is never too late to give up prejudices. 放弃偏见永远不晚。 九、 more often than not意为 “常常,往往” John is a good swimmer. He wins more often than not. 约翰是个游泳健将,他常常在比赛中获奖。 The street is crowded more often than not. 这条街常常很拥挤。 十、 否定词＋比较级( 相当于最高级) I couldn’t agree more. 我非常同意。 Nothing is more valuable than health. 健康是最宝贵的。 十一、 not a little意为 “很,很多” He is not a little tired. 他非常累。 He has not a little experience. 他有着丰富的经验。 十二、 某些不用回答和表达说话人感情的疑问句 1. 否定修辞性疑问句表示非常强烈的肯定。 Who does not know? (=Everybody knows.) 谁不知道?(意思是“人人知道”) 2. 否定感叹疑问句表示的肯定。 Isn’t that beautiful! 多么美丽呀! Isn’t she a sweet girl! 她多么可爱啊! 注：这种疑问句用来回答别人的问题或对别人的谈话做出反应,强调自己和对方意见一致。 ---Lovely day, isn’t it? 天气真好啊,是不是? ---Yes, isn’t it! 是啊,真好! 3. 祈使疑问句。 Won’t you have some beer? 请喝点啤酒吧！ Won’t you sit down! 请坐呀! 十三、否定的习惯用语表示的肯定 有些习惯用法,虽然形式上是否定的,但意义却是肯定的。 He’ll be at home now, as likely as not.(=He’ll probably be at home now.) 他很可能现在在家。 本文来源：https://www.wddqw.com/doc/62cf212f15fc700abb68a98271fe910ef02dae72.html