关于“Wh-疑问词+to不定式”结构的独立句地位

■倪肖丁

英语基础语法告诉我们，类似what to do, how to use the dictionary这样的结构一般只用于以下两种情况：1. 用作非独立分句，在句中充当一个成分，例如主语、宾语或表语等；2. 用作指导性标题（directive headings），即文章或段落的标题以及书名等。但不能用作独立的句子。

例如，Practical English Usage指出：We do not usually begin a direct question with How to ... ?, What to ... ? etc.  After question words, we often use shall and should.

How shall I tell her? (NOT  How to tell her?)

What shall we do? (NOT  What to do?)

Who should I pay? (NOT  Who to pay?)

但事情恐怕没有这么简单，一些权威语法著作给出了截然不同的说法。

CGOEL(§11.4)指出：Wh-questions (except for why-questions) without a subject and with a to-infinitive as the verb are occasionally found as inquiries。例如：

What to do next? ['What should I/we do next?']

Who to see?

Which way to go?

CGEL在 Open interrogatives一节中谈到开放式疑问句有可能被不同程度的简化时，介绍了相关句式。例如：

Why make such a fuss?

当然，此处的make...是无to不定式（a bare infinitival），那是因为习惯上why后不能跟 to不定式。但CGEL接着又说：to-infinitivals are also possible。例如：

How to explain his attitude?

在Infinitivals一节，CGEL又谈到了这个问题。例如：

What to do in the event of fire                    [titular]

How to persuade her to forgive him?         [main clause]

前一例是非句子结构（non-sentential construction），CGEL称之为titular，即CGOEL所称之directive headings，指的是文章或段落标题及书名等，其后没用标点符号；后一例是句子（a sentence），其后用问号。

Essentials of English Grammar(2006)-也指出：An infinitive sometimes by itself serves to form an independent sentence. Thus in a question:

What to do?  Where to go? 

How to get rid of that bore?

Why not go at once? (=Why should you not, or Why do you not, go?)

Practical English Usage是非常不错的英语惯用法专著，而CGOEL和CGEL更是当代英语语法杰作。如此看来似乎神仙打架了。

究竟孰是孰非，我们可以在英语使用实践中去求证。

根据CGEL关于这类不定式结构有文学风格的提示，我们在英文小说中的确发现有不少的用例。以小说The Thirteenth Tale为例，这一结构的使用现象颇为常见。现摘录几例如下：

（01）He couldn’t afford to make her cry in the presence of his father, and since she rarely left her father’s side, Charlie was faced with a difficulty. How to get her away?

（02）I seemed to wake up. “The thing is, Aurelius, she’s not well.”

“Ill? Then you must take me to her. Without delay!”

“Not ill, exactly.” How to explain? “She was injured in the fire, Aurelius. Not only her face. Her mind.”

（03）In my arms the baby stirred and opened his mouth to mewl. What to do? Behind Adeline’s back I softly retreated, then fled to the kitchen.

（04）I backed out of the doorway, not caring about the nettles and the thorns. I couldn’t wait to get away from the sight of him. But his image stayed with me and, though I ran, it seemed impossible to escape his hollow, one-eyed stare.

Where to find comfort?

There was a house I knew. A simple little house in the woods. I had stolen food there once or twice. That was where I went.

其它英文小说和普通读物中这类问句也不少见。

由此可知，“Wh-疑问词+to不定式”结构除了作为非独立分句和指导性标题以外，也可被用作独立句子。

既然如此，PEU怎么会郑重其事地对此予以否定呢？其实，这与这种结构用作独立句子的特殊语用功能有关。

从句（01）至（04）可以看出，当采用“Wh-疑问词+to不定式”结构做独立句子时，都类似于叙述过程中无须他人回答的“独白”，只表明说话者在对这一问题进行思索或设问。同时，在行文逻辑上通常也起到上下文衔接的作用，因为接下来很有可能描述该问题的解决之道。

例如句（01）讲的是哥哥查理打算把自己的妹妹伊莎贝尔作为其恶作剧的对象，但是妹妹几乎总是跟在父亲身边。查理可不想当着父亲的面把妹妹弄哭。“怎么让她从父亲身边离开呢？”显然这不是查理在向谁提问，也不可能希望从父亲、妹妹或任何其他人那里得到这一问题的答案。这是他内心在思索的一个问题，小说中可视为人物内心独白的描写。

句（2）的How to explain?（怎么向他解释呢？），句（3）的What to do? (怎么办？)，句（04）中的Where to find comfort?（到哪儿寻求安慰呢？）也具有类似的特征。

又例如：

（05）Divide it in halves, give half as the share of labor, the surplus left you will be greater, and the share of labor will be greater too. And to do this one must lower the standard of husbandry and interest the laborers in its success. How to do this?—that’s a matter of detail; but undoubtedly it can be done.’ (Anna Karenina)

句（05）讲的是如何让农场主和农民双双增加收入的思路：降低畜牧养殖的标准并使农民从自己的成功中获益。“怎样才能做到这一点？”这只是细节处理的问题，但毫无疑问是可以做到的（it can be done）。显然，说话者是在设问，抑或转述并试图解除他人的疑虑，而不是在向谁讨教答案。

这种“Wh-疑问词+to不定式”问句的功能和语用特色在一些英语语法学家的著述中是有所提及的。

CGEL在解释How to persuade her to forgive him? 这类问句时指出：By virtue of forming a sentence, it will normally have illocutionary force: it's a matter of asking, or at least wondering. This type is somewhat rare and literary; one case of it is in interior monologue, where one is pondering over a question. The meaning here is essentially "How could he persuade her . . .?" （大意为：使用这种句式具有“语内表现行为”（或“言外之意”）的作用：这是一个要解决或思考的问题。这种问句不常见，带有文学色彩。一种情况是内心独白，即在思索这个问题。How to persuade her to forgive him? 的意思基本上就是"How could he persuade her . . .？）

这里有个词illocutionary，可译为“言外之意的”或哲学和语言学术语“语内表现行为的”。指的是在特定语境中，一说出即完成的表达行为。这通常意味着不会接下来索求答案，至少从这一句式的实际使用情况看如此。也有语法学家也把这种现象视为自由间接引语的一种表现方式。

鉴此，“Wh-疑问词+to不定式”问句似乎不宜作为普通疑问句来向他人提问，以获取自己并不知道的答案。估计正是从这个意义上，PEU否定了How to tell her?和What to do?等等用法。可惜的是PEU并没有在其叙述中明确提到这一点。

那么，除了用作CGEL提到的表示需要设问或思索的问题以及内心独白这种情况以外，“Wh-疑问词+to不定式”问句能否用作向听话人索取答案的真正意义上的疑问句呢？在CGOEL和CGEL的相关论述中我们还没有见到直接的、明确的结论，这似乎为不同可能性留出了一定的空间。但就本人而言，目前尚未见到使用的实例，也不建议这样用。