■ let alone

1) 前面肯定了，后面再进一步肯定，可以说 even more so, still more, much more(much 没有加强语气), most of all，尽管形式上仍然是副词短语，实际上已经使起着连词的作用。但是后两者较少这样用作连词短语，前者则用得较多。

• This is something that will be enjoyed by younger audiences, but even more so with older audiences.这是年青观众会欣赏的，但是老年观众更会欣赏。
• This strategy makes a great deal of sense, even more so when considered from a long-term perspective.这种战略是很能起作用的，如果从长远的角度来看，作用就更大。

2) 前面否定了，后面进一步否定，可以说 still less 或 much less (much 也没有加强语气), least of all，也是作为连词短语。通常后面接上的是一个名词成分或状语成分，甚至可以是谓语动词成分。如果是个句子，要主谓颠倒。

• It is far from my thought to cast a veil over these misdeeds, which are such as to make the conscience of mankind shudder with horror for ever; still less will I endeavour to minimise the degree of guilt of the actors in the great drama. (British Prime Minister David Lloyd George)这些恶行，足以使得人类的良知永远为之震惊发抖，我绝不打算拿一块纱巾加以掩盖；对于那些参与这场大规模惨剧的操作者，我更不会设法减轻他们的罪责（后接整句，倒装）。
• I cannot go far in my analysis without drawing on interpretations that have not yet been adequately published, still less widely discussed or rigorously criticized and evaluated.我要进一步进行分析，就无法不引用一些尚未正式发表、更未经过广泛讨论或严格批判与评价的解读论著（后接动词过去分词）。
• I would not belittle, still less deny, the many admirable products this technology has brought forth, products that a self-regulating economy would make good use of.我不打算贬低，更不打算抹煞这种技术所已经产生的许许多多了不起的产品，对于这些产品，凡是自我调节的经济，都会好好加以利用（后接谓语动词词组中的动词不定式）。
• The cloud of treason hanging over him was enough to guarantee that no one ever trusted, much less listened to him ever again.悬在他头上的背叛乌云，已足以保证谁也不会再信任他，更不会再听他的（后接谓语动词）。
• I'm not blaming anyone, much less you.我不是指责任何人，更不是指责你。（后接作为宾语的代词）
• Such large questions are never easy to approach, much less to answer... (Ian P. Watt, The Rise of the Novel, p.9)这样的大问题，从来都是不容易对待的，要回答更是不容易…

前面不是明确的否定，只是疑问反诘或“准否定”，这个用法同样适用。

• When our headlights flashed, the deer barely blinked, much less/still less moved.我们的车前灯闪亮时，那只鹿眼睛都不眨一下，更别说动一下了（后接谓语动词）。
• In American memory President Coolidge is, to put it mildly, hardly an object of pride or admiration, still less of veneration.在美国人的回忆中，柯立芝总统，说得客气点，很难使人以他为荣或是对他感到钦佩，更难以使人崇敬他（后接作为定语的介词词组）。
• Under what circumstances does the CEO owe the employee anything, least of all an explanation for his actions?身为总经理，哪能欠区区一个雇员什么东西，更何况是对自己的行动要对他说明理由？

但是，要注意，所谓前面有否定，是对整个前面句子的否定，如果前面只有一个否定作用限于本身的单词而没有否定全句的否定词，则仍然要当作“前面肯定了，后面进一步肯定”处理。

• It is impossible to finish this work in a week, even more so in two days.这个活儿，一个星期是做不完的，更别说两天了。

这是因为 impossible 更进一步是 more impossible 而不是 less impossible（其实 impossible 本身就不容许有比较级，这里只是就行文语气而言）。

3) 不分“前面肯定了，后面进一步肯定”或是“前面否定了，后面进一步否定”，都可以用 let alone。后面不一定要名词成分，也可以是副词成分，甚至可以插入谓语动词词群之中。

用于进一步肯定的。

• It was folly to have thought of going in the first place, let alone staying. (Kate Chopin, The Awakening and Selected Short Stories)本来想到要去，就已经够愚蠢的了，更何况想到要留在那里。
• He knows every cabbage stump in th' gardens, let alone th' people. (Frances Hodgson Burnett, The Secret Garden)他对菜园里的每一棵白菜茬都熟悉，更别说对人了。
• He will, sir, for the hatred and malice that he bears to you; let alone the pleasure of doing a bad action, which to him is its own reward. (Charles Dickens, Barnaby Rudge—A Tale of The Riots of 'Eighty)先生，他会这样做的，因为他恨您，对您抱有恶意；更何况他又以干坏事为乐，坏事对于他，本身就是一种奖赏。
• The striking victory over a menacing combination of Turks and Arabs in the north, won by troops under the command of Lord Hastings, the veteran of so many striking victories, was already spread by the newspapers all over the Empire, let alone to this small garrison so near to the battlefield. (Gilbert K. Chesterton, The Man Who Know Too Much)那位身经百战军功彪炳的哈斯汀斯爵士所率的大军，击败土耳其人和阿拉伯人声势汹汹的联军，大捷的消息，已经传遍了帝国各地的报纸，更不用说传到了如此靠近战场的这个小小驻兵点。
• She was, on the contrary, inclined to be silent; she shrank from expressing herself even in talk, let alone in writing. (Virginia Woolf, Night and Day)她则相反，倾向于沉默寡言；她甚至在言谈中也尽量少说话，书面上就更不用说了。
• I would have you to know, clerk, that I am a free English burgher, and that I dare say my mind to our father the Pope himself, let alone such a lacquey's lacquey as you. (Sir Arthur Conan Doyle, The White Company)我要让你这个办事员明白，我是个自由的英格兰市民，心里有什么话，我在教皇他老人家面前也敢一古脑儿说出来，更不用说在你这个奴才的奴才面前了。

但是，从上面用于进一步肯定的例句来看，let alone 总是带有“从高往低处说”的“降级”意义，而不是“更上一层楼”那个意义上的进一步肯定。因此，也有人（例如加州大学伯克利分校的 Maziar Toosarvandani）主张 let alone 仍然应该列入“否定极性项”(Negative Polarity Items, NPIs)的范畴。

用于进一步否定的。

• I wouldn't go out with him, let alone marry him.我不会跟他一起出去，更不会嫁给他。
• She's too good and holy for any man, let alone me. (George Eliot, Adam Bede)她太美好，太神圣了，哪个男人都配她不上，更别说我了。
• The human animal is a strange spectacle to behold, let alone comprehend. (Mr. and Mrs. Julius Haldeman, Dust)人类这种动物，是一种不容易察看，更不容易理解的奇景。
• But when we neared the coast we discovered no indication of any human habitations whatever, let alone a city. (Edgar Rice Burroughs, The Lost Continent)我们靠近海岸的时候，发现那里渺无人烟，更别说有什么城市了。
• The Moors have a small opinion of England, France, and America, and put their representatives to a deal of red-tape circumlocution before they grant them their common rights, let alone a favor. (Mark Twain, The Innocents Abroad)摩尔人瞧不起英国、法国和美国，就采取繁文缛节和迂回的办法来折腾这些国家的代表们，不给与他们以通常的权利，更别说给他们优待了。
• When he looked straight at you, you didn't know where you were yourself, let alone what he was looking at. (Gilbert K. Chesterton, The Innocence of Father Brown)当他直瞧着你的时候，你简直不知道自己身在何处，更别说知道他在瞧着什么了。

也可以用于带否定语气的反问。

• Think ye(=Do you think) that your beggarly feast was worth three pounds, let alone three hundred? (Howard Pyle, The Merry Adventures of Robin Hood)你们以为你们那顿叫化子般的餐宴值三英镑吗？更别说三百英镑了。

有时候前面的一个否定只是准否定，但也可以用 let alone 来表示进一步的否定。

• Little attention was paid to it, and 10 years passed before the existence, let alone the exact functions of these receptors, non-committally named alpha and beta, was recognized.人们不怎么注意这件事情，这些不明不白地叫做α与β的接收器，经过了十年之后，其存在才被承认，至于其准确的功用，那就更不那么容易承认了。
• On what the boss pays us, we are lucky to be able (= we are lucky if we are able) to keep body and soul together, let alone feed a family.靠老板付给我们的工钱，我们能自己糊口就算运气的了，哪还谈得上养家。

这里的 are lucky to be able to 带有“能如何如何就算运气，不一定能做到”的准否定语气（关于 we are lucky to be able = we are lucky if we are able，参见 lucky 条）。

要注意的是，这个 let alone 已经逐渐成了一个比 not 更进一步否定的副词短语，甚至可以放在谓语动词词组之内。

• Country A still has not signed a peace treaty with country B, let alone established full diplomatic relations.甲国尚未同乙国签订和约，更没有建立完全的外交关系。
• I've not even read the first Chapter, let alone finished the book.第一章我还没有看，更谈不上看完这本书了。
• No one had even heard of Pat Weaver, let alone seen him.没有谁听说过帕特·韦维尔，更没有见过他。