let alone 是一个固定短语,意思是"更不用说" 。如:

　　1. 英国人自己也常常不能确定什么是俚语,更不用说外国人了。
　　Englishmen themselves are often uncertain what is slang and what isn't, let alone foreigners.(《英汉大词典》)

　　2. 他连买一辆旧汽车的钱都不够,更不用说买一辆新的了。
　　He didn't even have enough money to buy a used car, let alone a new one. (《英语惯用短语词典》)

　　3. 这婴儿连走路都不会,更不用说跑了。
　　The baby can't even walk, let alone run.(《简明英语短语辞典》)

　　除let alone外,"更不用说" 在英语中还可用其它一些短语来表达,常见的有not to speak of, not to mention, to say nothing of, much/still/even less, much/still more等。现结合例句简介如下:

　　一﹑not to speak of (后接名词)

　　1. 他的朋友和同事都会为此事难过,更不用说他的父母了。
　　His friends and colleagues will be very upset, not to speak of his parents. (《英汉大词典》)

　　2. 这位学者精通拉丁语,至于他的本族语--英语就更不用说了。
　　The scholar is well versed in Latin, not to speak of English which is his native language.(《英语惯用短语辞典》)

　　3. 他会说德语和法语,更不用说英语了。
　　He can speak German and French, not to speak of English.(《最新高级英汉词典》)

　　二﹑not to mention或without mentioning (后接名词)

　　1. 他们连法国香槟酒也端来给我们喝,更不用说平常的鸡尾酒了。
　　We were served French champagne, not to mention usual cocktail.(《英汉大词典》)

　　2. 这孩子算术还没学会,更不用说代数了。
　　The boy has not learnt arithmetic, not to mention algebra.(《新英汉词典》)

　　3. 大人﹑小孩都不赞成这个建议,更不用说年轻人了。
　　Old folks and children alike are all against the proposal , not to mention the youth.(《英汉六用词典》)

　　三﹑to say nothing of (后接名词或动名词)

　　1. 这个句子别扭得很,更不用说它语义晦涩了。
　　This sentence is very awkward, to say nothing of its being obscure. (《简明英语短语辞典》)

　　2. 许多人受了重伤,更不用说房屋的毁坏了。
　　Many people were badly hurt, to say nothing of damage to the building. (《最新高级英汉词典》)

　　四﹑much/still/even less (后接代词﹑动词或句子)

　　1. 我想都未想到它,更不用说讲到它了。
　　I never think of it, much less say it.(《英语惯用短语辞典》)

　　2. 她连自己的工作都不能及时完成,更不用说帮助别人了。
　　She can't finish her own work in time, even less help others.(《英语惯用法大词典》)

　　3. 他看都看不懂英语,更不用说教了。
　　He can't read English; still less can he teach it.(《英汉六用词典》)

　　五﹑never mind(常用于口语)

　　I can't walk, never mind run.我连走都不行,更不用说跑了。(《英汉大词典》)

　　六﹑much/still more(用于肯定句,后接名词或介词短语)

　　1. 她法语都懂,英语就更不用说了。
　　She knows French, much more English. (《最新高级英汉词典》)

　　2. 他对我很和善,更不用说对我哥哥了。
　　He is kind to me, still more to my elder brother.(《英语惯用短语词典》)

　　七、much/still less(后接动词或句子)

　　1. 她连饮料都不愿喝一杯,更别提留下吃饭了。
　　She wouldn't take a drink, much less stay for dinner.(《英汉大词典》)

　　2. 法语不是法国人的私有财产,英语就更不成其为英国人的私有财产了。
　　French is not the private property of Frenchmen, and still less is English the private property of Englishmen.(《英汉大词典》)