not to say/let alone

let alone 一般不能用来代替 not to say。原因有二:一是词义不同,二是用法不同。

let alone 的意义是: not to mention, much less, to say nothing of(更不用说)。例如:

1. I've not even read the first chapter, let alone finished the book. (CGEL) 我连第一章都没有读完，更不用说看完全书了。

2. "What excuse did John offer for his rudeness at the committee meeting?" "He didn't even mention it, ____ explain it."

A. let alone B. and even not C. or not D. as opposed to (TOEFL)

3. He can't speak his own native language well, let alone French. (Whitford) 他连他的本族语都说不好，更不用说讲法语了。

4. I can't afford wine, let alone champagne. (NCCED) 我连葡萄酒都买不起，更不用说买香槟酒了。

5. He hasn't enough money for food, let alone amusements. (Palmer) 他连伙食钱都不够，更不必说娱乐了。

6. There's no room for her, let alone the children. (Chambers) 连给她住的房间都没有，更不用说孩子们了。

而 not to say 的意义则是: even, perhaps even, and almost, if not to use a more moderate word or statement than(甚至, 甚至也许, 甚或, 即使不……也, 简直可以说)。

1. His language was irreverent, not to say blasphemous. (WBD) 他的言语即使不算渎神，也是不够虔诚的（他的言语是不够虔诚的，甚或是渎神的）。

2. He is unkind, not to say cruel. (MED) 他即使不算残忍，也是够刻薄的了。

3. It is warm, not to say hot. 虽不能说热,但很暖和了。(《远东英汉大辞典》)

to say nothing of

4. He sounded impolite, not to say rude. (LDCE) 他的话听起来很不礼貌，甚至有些粗鲁。

5. It would be foolish, not to say mad, to sell your car. (LDCE) 你要是把你的汽车卖掉，即使你不是疯了，那也是很愚蠢的。

6. His manner was discourteous, not to say offensive. 他的态度很不礼貌，甚至令人讨厌。

7. His manner was unwelcoming $\$left\{ \begin{array}{l} if not \\ not to say \end{array} \right\} downright rude. (CGEL) 他的态度即使不是太粗鲁，也是很令人不愉快的。

从用法上看, let alone 一般用于否定句。让我们先来看一看 EED 对 let alone 的解释: If you say that something is not the case, let alone something else, you mean that since the first thing is not the case, the second thing cannot be, because it is difficult or unusual. (如果你说某件事不是某种情况, let alone 其他事情, 那你的意思是: 由于第一件事不是某种情况, 所以第二件事也不可能是那种情况, 因为后者更加困难或不平常)。例如:

1. I had never seen him, let alone spoken to him. (EED) 我那时从未看见过他，更不用说同他谈话了。

2. The baby can't even walk, let alone run. (LDCE) 这婴儿还不会走路，更不用说跑了。

3. I can't add two and two, let alone fractions. (DAI) 我连二加二都不会, 更不用说分数了。

4. She will not help her brother, let alone a stranger. (ELD) 她连她的亲弟弟都不愿意帮助,更不用说陌生人了。

let alone 用在肯定句中的情况比较罕见：

1. It will cost us a fortune for the food, let alone the wine! (Chambers) 单食品就得花去我们一笔款，更不用说酒了！

2. It would have been a hot day for summer, let alone early spring. (WBD) 那一天即使对于夏天来说都是很热的，更不用说早春了。

3. There were seven people in the car, let alone a pile of luggage and three dogs. (ALD) 那部汽车载了7个人，还有一大堆行李和三只狗。

不难发现,由于词义和用法的不同,let alone 是不能代替 not to say 的。

还应指出，let alone 与 not to say 也有共同之处，就是它们都是准并列连词（quasi-coordinators），它们可以连接各种句子成分或各类词。绝不要把 not to say 中的 say 看作及物动词，因而认为它只能后接名词短语。请分析上述各句中 let alone 和 not to say 所连接的句子成分和连接词项的词性。