英語中有些句子沒有含否定式卻表達(dá)了否定意義,這一情況通常被稱為暗否定或隱藏否定 (concealed negation)。熟悉了這些常見的暗否定句子結(jié)構(gòu)會(huì)有利于英語學(xué)習(xí)者對(duì)英語句子的理解，從而更好地掌握英語。常見的暗否定結(jié)構(gòu)有以下一些形式:
一.有一些詞或短語可起到表達(dá)暗否定的效果。
⒈句中用“the last、the least、the limit”等詞組可表示強(qiáng)烈否定，意思是：“最不……”。例如：
You're the last one that I want to see in the world. （你是我最不愿見的人。)
He spoke ill of me, and that's the limit. (他說我的壞話，那真讓人無法忍受。)
⒉ but for（要不是/倘若沒有）后接名詞或代詞、but that（要不是/倘若沒有）后面應(yīng)跟從句，二者均表示虛擬的條件，謂語動(dòng)詞須用虛擬語氣結(jié)構(gòu)。
But for your help, I couldn't have succeeded.
But that you had helped me, I couldn't have succeeded.
要不是你的幫忙/如果沒有你的幫忙，我是不會(huì)成功的。
⒊ anything but（決非,決不，一點(diǎn)也不），but后跟名詞/代詞/形容詞，有強(qiáng)勢(shì)否定之義。
My father likes anything but beef. (我父親最不喜歡吃牛肉。)
The painting is anything but beautiful. (這幅畫根本就算不上美。)
⒋ everywhere but 表示“決不在……”
He will work everywhere but in Shanghai. (他根本不愿意在上海工作。)
⒌ let alone“更不必說”
He can't ride a bicycle，let alone a motorbike. (他不會(huì)騎自行車,更別說摩托車了。)
二.有些連詞也可以表達(dá)暗否定義，比較常見的連詞有unless、since、before等。
⒈ unless 引導(dǎo)的從句，意為“除非”, 相當(dāng)于if...not...
He never speaks unless he is spoken to.
＝He never speaks if he isn't spoken to. (如果別人不和他說話,他就不說話。)
⒉ since引導(dǎo)的狀語從句中，若謂語動(dòng)詞為延續(xù)性動(dòng)詞且為一般過去式時(shí)，從句所表示的時(shí)間從動(dòng)作終止或狀態(tài)不再繼續(xù)時(shí)算起,用否定翻譯法翻譯句子。
We've been out of touch since we lived together(自從我們不在一起住，就失去了聯(lián)系。)
對(duì)比：It's 6 years since I graduated from Beijing University。
（我從北京大學(xué)畢業(yè)到現(xiàn)在已有6年時(shí)間了。）
⒊ before引導(dǎo)的狀語從句也可以表達(dá)暗否定義
The audience had all left before the play finished. （戲劇還沒有結(jié)束觀眾就已經(jīng)走光了。）
Three months went by / on before Aqiao knew it. (不知不覺中阿巧度過了三個(gè)月。)
三.有一些比較結(jié)構(gòu)也可表達(dá)暗否定。
⒈more...than...表同一人或事的不同性質(zhì)或特征。
Lu Bu is more brave than wise. (呂布有勇無謀。)
⒉no+形容詞/副詞的比較級(jí)+than，對(duì)雙方進(jìn)行否定，意思為：并不比
Tom is no cleverer than his brother. （湯姆并不比他兄弟聰明．（一樣笨/都不聰明．）
⒊“less+形容詞或副詞原級(jí)+than”結(jié)構(gòu)表示否定的對(duì)比。
The results left us less than satisfied. （結(jié)果讓我們不太滿意。）
⒋用“still、much、even、 a little”等表示否定程度。
She hasn't cleaned her own room, still less mine.
(她自己的房間都沒有打掃，更不用說我的了。)
對(duì)比：We should thank him for his advice, still more for his financial help.
（我們應(yīng)該感謝他的建議，更要感謝他的資金援助.)
★ still more用于肯定句, still less用于否定句。
四.某些固定的結(jié)構(gòu)也可以表達(dá)暗否定。常見的有“too...to...”相當(dāng)于so...that...can't或not...enough to...
⒈ It was too difficult for us to work out the problem.
注意對(duì)比：He is too glad to receive your letter. （他收到你的來信非常高興。）
⒉prefer ...to .../ prefer to do ...rather than do .../ would rather do…than do/ prefer doing rather than doing。寧愿…也不愿…
eg: ① The workaholics prefer to tire themselves out in work rather than sit doing nothing. (工作狂們寧愿累死在工作中也不愿無所事事。)
② The Red Army soldier would rather die than give in.
五.某些情態(tài)動(dòng)詞跟動(dòng)詞完成式也可表否定意義, 常見的有:
should have done (本應(yīng)做而沒做）
need have done（本需要做而沒做）
could have done(本能夠做卻沒有做/可能已做過)
would like to have done (本愿意已做過而沒做)等。
① I would like to have gone to your birthday party last night， but I had to do extra work.
(昨天晚上我本來要參加你的生日晚會(huì)的，但因?yàn)榧影喽鴽]有去成。)
②Our team could have won the football game if it had not been because of the absence of Jack.(要是杰克不缺席，我們就能贏那場(chǎng)球賽。)（實(shí)際上我們隊(duì)沒有贏。）
③As his best friend，you should have help him out.
(作為最好的朋友，你本應(yīng)該幫助他擺脫困境的。) （實(shí)際沒有幫助他。)
六.英語中有些詞或短語在形式上是肯定，但卻具有否定意義。常見的有：
“be inferior / second to， be junior to， fail to，differ, escape，keep from，desert， be blind to， be absent from， live up to， be short of， miss， deny， refuse， let alone， much／even / still less 等。
①I'm junior to Xiao Wang. (我沒有小王年齡大。)
②The boss was blind to Tom's excuse. (老板對(duì)湯姆的借口置之不理。）
③He is second to everyone else in maths in Class 1.(他的數(shù)學(xué)在一班里是最差的.)
七.部分介詞或介詞短語表示暗否定，常見的表達(dá)暗否定意義的介詞有：
above，under，over，below， beneath， beside， behind，past， against，except，beyond，from，far from，off，to， without， out of等。 一些介詞和名詞連用時(shí)所表示的暗否定能達(dá)到一定的修辭效果，如: beyond words (beyond description / praise), beneath notice，in spite of， instead of， out of work / power.
①This maths problem is beyond me.
②——Are you satisfied with the speech？
——No,far from it. I've never seen a more boring one.