英语教学法原著选读52：克拉申二语习得五假说之四·输入假说3（Input Hypothesis）

有料、有趣、有心的“三有”新金星人武太白现开放个人QQ、微信（均为1601918196），欢迎英语教师和英语专业师范生添加，共同探讨、提高。

导读：本篇是二语习得泰斗Stephen D. Krashen的著作《二语习得原则与实践（Principles and Practice of Second Language Acquisition）》第二章“第二语言习得理论”A节“有关第二语言习得的五个假说”中的第四个假说，探讨的是语言习得的实际过程。当代外语教学的基石i-->i+1，就是在这个假说中提出来的。按照这一假说，只要提供足够的、与真实语言环境相匹配的输入，学习者就能够自然地从现有的语言能力（i）进步到略高一层次的语言能力（i+1）。

输入假说的原文很长，将分三期刊出，本篇是第三篇。本文首发于“武太白金星人”微信公众账号，把本文分享到您朋友圈后关注该公号（文末有关注方法）并回复“01”（大小写没关系，引号不要，请确保没有多余空格）即可收到上文图书的英文原版全本PDF。该书仅供个人学习研究使用，请勿用作商业用途，并请于下载24小时后自觉删除。祝朋友们学习进步！

------------------------

原文

(iii) Evidence from second language acquisition: the silent period and L1 influence. The input hypothesis is also consistent with other findings and hypotheses in second language acquisition. One of these can be termed the "silent period", a phenomenon that is most noticeable in child second language acquisition.

It has often been noted that children acquiring a second language in a natural, informal linguistic environment may say very little for several months following their first exposure to the second language. What output there is consists usually of memorized language, whole sentences learned as if they were one word. Hatch (1972), for example, reported that Paul, a five-year-old Chinese speaker acquiring English as a second language, did not really use "creative" language for his first few months in the United States. His only output was memorized sentences, such as

Get out of here. It's time to eat and drink.

He had clearly learned these as whole utterances without a real understanding of their components (e.g. he probably would not understand the word "out" or "time" if it were used in another sentence). Such memorized sentences were probably very useful for Paul, both in the classroom and playground. When "real" language did start to emerge, it looked very much like first language development, with short, simple sentences such as

This kite. Ball no.

The explanation of the silent period in terms of the input hypothesis is straight-forward--the child is building up competence in the second language via listening, by understanding the language around him. In accordance with the input hypothesis, speaking ability emerges on its own after enough competence has been developed by listening and understanding. We should note that case histories dealing with children acquiring second languages (see also Hakuta, 1974; Ervin-Tripp, 1974) agree that several months may elapse until they start talking, and that the speech that emerges is not error-free. This finding has important pedagogical considerations, as we shall see in Chapter III.

Adults, and children in formal language classes, are usually not allowed a silent period. They are often asked to produce very early in a second language, before they have acquired enough syntactic competence to express their ideas. According to a hypothesis first proposed by Newmark (1966), performers who are asked to produce before they are "ready" will fall back on first language rules, that is, they will use syntactic rules of their first language while speaking the second language.

Stated more formally, an acquirer will substitute some L1 rule for i + 1, a rule of the second language, if the acquirer needs i + 1 to express himself but has not yet acquired it. The L1 rule used may be quite similar to the L2 i + 1, but may also differ in certain ways. When the L1 and L2 rules are different, the resulting error is referred to often as "interference". But according to Newmark, it is not interference at all; it is not the result of the L1 interfering with second language performance, but the result of ignorance--the lack of acquisition of an L2 rule that is needed in performance.

(iv) Advantages and disadvantages of L1 rule use. The substitution of some L1 rule for some i + 1 has both advantages and disadvantages. The advantages are short term, however, while the disadvantages appear to be quite serious.

One obvious advantage is that the use of an L1 rule allows the performer to "outperform his competence", to meet a practical need in L2 communication before he has acquired the relevant i + 1 rule. When the L1 rule used is identical to a rule in the L2 ("positive transfer"), the performer seems to have got something for free. Even if the L1 rule is not the same as the L2 rule, one could argue that the performer still comes out ahead, as, quite often, he can still communicate his point despite the incorrect form.

Another advantage is that the early production allowed by the use of L1 rules also helps to invite input--it allows the performer to participate more in conversation, and this could mean more comprehensible input and thus more second language acquisition.

There are real disadvantages to falling back on the L1, however. First, the L1 rule may not be the same as an L2 rule, as noted above, and errors can result. The conscious Monitor can note and repair these errors in some cases, but not all, since, as we have seen the constraints on Monitor use are severe. Thus, use of L1 rules requires constant vigilance on the part of the Monitor, and is an awkward way to produce formally correct sentences in a second language. (Note that Monitor correction of such errors will not, according to the theory, produce acquisition, or permanent change. It will not eradicate the L1 rule, even if done effectively over long periods of time. Real acquisition comes only from comprehensible input.)8

There may be another serious disadvantage to the use of L1 rules in second language performance. Even if the L1 rule is similar to an actual L2 rule or transitional form, it is not clear that these rules will help the acquirer progress--they may not take the place of "true" L2 rules in the developmental sequence. In Krashen (1982) I discuss the hypothesis that acquisition requires a comparison between i and i + 1 (Clark and Andersen, 1980; Lamendella, 1979). It may be the case that the "distance" between i and i + 1 cannot be too great--i and i + 1 can only differ in small ways. Transitional forms, I hypothesize, may be useful in that they can temporarily serve as i, helping to decrease the amount of distance between i and i + 1.

If, for example, the target rule in English is the negative (i + 1, presented to the system by input), the intermediate form no + v (provided by the creative construction system internally) may be closer to the mature negative form. The acquirer may thus use no + v at i, rather than a more primitive form of the negative (e.g. no + S).

If transitional forms can temporarily serve as i, the next question is whether L1 rules, even when they happen to be similar to L2 rules or transitional forms, can perform this function. The answer may be "no". For example, Spanish speakers often have a long period in their acquisition of English in which they produce no + v for the English negative, a structure that is similar to a transitional form in English as a first and second language (Schumann, 1979). It may be the case that earlier no + v performance is the use of the L1 rule, while later no + v performance is the true intermediate form. It may be the case that only the latter can help the system "move forward".

To summarize, use of L1 rules is hypothesized to be the result of falling back on first language knowledge when a second language rule is needed in production but is not available. It may temporarily enhance production, but may not be real progress in the second language. The real cure for "interference", according to Newmark, is not drill at the points of contrast between the two languages (Newmark and Reibel, 1973, p. 239). Drill will, at best, produce learning, and, as we have seen, this is only a short term cure. The real cure "is simply the cure for ignorance" (Newmark, 1966, p. 81): real language acquisition. This can happen only when the acquirer obtains comprehensible input.

(v) Applied linguistics research. The input hypothesis is also consistent with the results of what can be called "method comparison" experiments. Several scholars and groups of scholars have attempted to determine directly which teaching methods are best by simple comparison. Groups of students studying second and foreign languages using two different methods are compared, both in long-term and short-term studies. We will have a detailed look at this research in Chapter V, but I will state my own conclusions in advance. My reading of studies comparing the more commonly used methods (audio-lingual as compared to grammar-translation or cognitive-code) is as follows:

(1) "Deductive" methods (rule first, then practice, e.g. grammar-translation and cognitive-code) are slightly more efficient than audio-lingual teaching for adults. The differences are often statistically significant, but are not huge. Students clearly make some progress using any of these approaches.

(2) For adolescents, there is no measurable difference.

I interpret this failure to find large differences in this way: none of the methods compared in these studies provides much in the way of comprehensible input! The input hypothesis predicts, moreover, that an approach that provides substantial quantities of comprehensible input will do much better than any of the older approaches.

There are several newer methods that do this, such as Asher's Total Physical Response Method (Asher, 1966, 1969) and Terrell's Natural Approach (Terrell, 1977). In these methods, class time is devoted to providing comprehensible input, where the focus is on the message and not the form, and students are not expected to produce in the second language until they themselves decide they are "ready". Reports confirming the superiority of such "input methods" have been appearing in the professional literature over the last ten years (e.g. Asher, 1972; Gary, 1975; Postovsky, 1974; more detail is provided in Chapter V). (The focus on comprehensible input is not the only reason for the success of the newer methods, however; see discussion below of affect, and Chapters III and V.)

Since the bulk of this book is intended to deal with implications of second language acquisition theory (Chapters III, IV, and V), this section should really be delayed until later. I cannot resist, however, briefly stating one implication here, since, in my opinion, the implications of the input hypothesis are truly exciting for all of us interested in language acquisition. Most important, the input hypothesis predicts that the classroom may be an excellent place for second language acquisition, at least up to the "intermediate" level. For beginners, the classroom can be much better than the outside world, since the outside usually provides the beginner with very little comprehensible input, especially for older acquirers (Wagner-Gough and Hatch, 1975). In the classroom, we can provide an hour a day of comprehensible input, which is probably much better than the outside can do for the beginner.

------------------------

译文

（iii）二语习得的证据：沉默期和一语影响。输入假说与二语习得的其他发现与假说也是相一致的。其中一种发现可以称为“沉默期”，是在儿童二语习得中最容易发现的一种现象。

经常有人指出，在自然的、非正式的语言环境中习得第二语言的儿童，在最初接触到第二语言后，可能几个月都说不了多少这种语言。能说出来的通常是记住的语言，是当成一个词来学习的整句。例如，哈奇（1972）报告说，一个学英语的五岁中国孩子“保罗”在他刚到美国的前几个月实际上并不使用什么“创造性”语言。他唯独的输出是好记的句子，比如“Get out of here. It’s time to eat and drink.”

他显然是把这些说法整个记住了，对句子的成分并没有真正理解（例如，要是“out”、“time”用在别的句子里，他可能并不理解）。这种熟记的句子对保罗来说可能很管用，不管是教室里还是操场上。当“真正的”语言出现的时候，看起来就很像第一语言的发展过程，会有简短的、简单的句子，如“This kite. Ball no.”

输入假说对这种沉默期的解释很直接——孩子正通过听力、理解周围的语言形成能力。与输入假说相一致，在通过听力和理解形成了足够的能力之后，口语能力就会自然形成。我们要注意到，研究儿童二语习得的个案历史一致表明，儿童要过几个月才开始讲话，而且所讲的话也做不到准确无误。这一发现对教学大有裨益，我们在第三章中会看到。

成人和儿童在正式的语言课堂里通常是没有机会过什么沉默期的。他们通常被要求很早就用第二语言输出，这时他们还没有形成足够的句法能力来表达自己的想法。根据纽马克（1966）首先提出的假说，被要求在“就绪”之前就输出的表现者会求助于第一语言的语法，即他们会在讲第二语言的时候使用母语的句法规则。

更正式地说，习得者会用一语规则替换i+1，如果他需要用来表达自己的i+1还未能习得的话。所使用的一语规则可能与二语i+1相似，但也可能在一些方面有所不同。一语、二语规则不同时，所产生的错误就称为“干预”。而纽马克则认为，这根本就不是什么干预；这不是一语干涉二语表现，而是缺乏能力的结果——缺乏对所需的第二语言规则的习得。

（iv）一语规则使用的好处与弊端。用一语规则替换i+1既有好处也有弊端。然而，好处是短期的，而弊端看上去可能会很严重。

一个明显的好处是使用一语规则能使表现者“超常发挥”，从而满足二语交际的实际需要，这时他还未曾习得所需的i+1。如果所使用的一语规则与二语规则相一致（“正向迁移”），表现者看上去就不费吹灰之力得到了新东西。即便一语规则与二语规则不同，也可以说表现者还是过关了，因为经常是即便语言形式错了，他还是能够把自己要说的东西表达出来。

另一个好处是使用一语规则达成的早期输出也能帮助吸引更多的输入——这使得表现者能够更多地参与对话，这可能意味着更多的可理解输入，也就是更多的二语习得。

然而，实在也有弊端会对一语造成影响。首先，一语规则可能与二语规则不完全相同，如上所述，从而可能会有错误。一些情况下有意识监控会注意到这些错误并加以改正，但不能全部改过来，因为如同我们讨论过的那样，监控的使用还是很受局限的。这样一来，一语规则的使用就要求监控时刻警觉，而这在以二语输入形式正确的句子方面是一种笨拙的办法。(注意，根据理论，监控对这种错误的修改并不产生习得，也不产生永久的改变。这种修改不会消除一语规则，即便长期有效地进行。真正的习得只有通过可理解输入才能够发生。）

在二语实践中使用一语规则可能还有一个严重的弊端。即便一语规则与实际的二语规则或过渡形式相类似，也不清楚这些规则是否会帮助习得者进步——在发展序列中它们可能取代不了“真正”二语规则的作用。在克拉申（1982）中我探讨了这样一个假说：习得需要对i和i+1进行比较。i和i+1之间的跨度可能不允许太大——i和i+1只能小有不同。我推论，过渡形式可能的用处是其能暂时作为i出现，帮助缩小i和i+1之间的跨度。

比如，假使英语中的目标规则是否定式（i+1，使用输入方式呈现到系统中），那么过渡形式no+动词（由内在的创造性结构系统提供）可能就更接近成熟的否定形式。这样习得者可能把no+动词作为i，而不是把更加原始的否定形态（如no+主语）作为i。

如果过渡形式能够临时作为i出现，接下来的问题就是一语规则，即便凑巧其与二语规则或过渡形式很近似，能否承担这一职能（能否作为i出现）。答案可能是“不能”。比如，西班牙语者经常在他们习得英语的过程中有很长一段时期用no+动词替代英语的否定式，这种形式与英语作为一语、二语的一种过渡形式很接近。可能早先的no+动词是一语规则的使用，而后来的no+动词是真正的过渡形式。可能只有后者才能帮助系统“前进”。

总结一下：一语规则的使用可以认为是在语言输出中需要二语规则却尚未习得时向一语求助的结果。这种使用能够暂时促进输出，却并非二语的真正进步。纽马克认为，对“干涉”的真正解决并非把两种语言的不同之处进行反复操练。操练最多也只能形成学得，而如同我们上面所见，这仅仅是短期效应。真正的解决之道是“就解决无知的问题”：真实的语言习得。这只能是在习得者获得可理解输入的情况下发生。

（V）应用语言学研究。输入假说与可称为“方法比较”的试验的结果也是一致的。多位学者、多个学者小组都试图用简单比较的方法直接确定哪种教学方法是最好的。各组学习二语、外语的学生使用两种不同的方法，进行相互比较，进行了长短期研究。我们将在第五章对此进行详细探讨，但我要在此提前说一说我的结论。我对比较常用方法（听说法，相对于语法翻译法或认知信号法）的研究的解读如下：

（1）对成人来说，“演绎性”方法（规则先来，然后练习，比如语法翻译法和认知信号法）比听说教学法稍微有效些。经常是差异有统计学意义，但并不大。学生使用任何一种方法都能取得明显进步。

（2）对青少年来说，没有可测量的区别。

我对找不出巨大差异的这种情况是这么解读的：研究中所使用的这些方法没有哪一种能提供大量的可理解输入！输入假说还预测，能够提供大量可理解输入的方法会比以上较传统方法中的任何一种都要好得多。

有好几种新方法能够做到这一点，比如阿舍的全身反应法，特雷尔的自然教学法等。这些方法把课堂时间用于提供可理解输入，重点关注内容而非形式，不要求学生以第二语言输出，直到他们觉得已“准备就绪”。十年来对此类“输入教学法”的优越性加以肯定的报告已经开始出现。（然而，对可理解输入的关注并不仅仅是新方法成功的唯一原因；可以看看接下来有关情感过滤的部分，以及第三章、第五章。）

因本书大部分意在探讨二语习得理论的意义（第三、四、五章），这一部分实际上应该要到后面才放上来。然而我却忍不住要在这里先说一个：在我看来，输入假说的意义对于我们这些对语言习得感兴趣的人来说实在是令人振奋的。最重要的是，输入假说预测，教室也可以成为绝佳的二语习得场所，至少也可以达到“中等”水平。对初学者来说，教室可能比外部世界还要好上许多，因为外部世界通常提供给初学者的可理解输入实在不多，对年长的习得者来说尤其如此。在教室里，我们可以提供每天一小时的可理解输入，这要比外部世界能为初学者所做的多得多。

-----------------------

长按此处二维码即可识别并轻松关注“武太白金星人”微信订阅号，接收每日高价值、高格调英语学习、教学、儿童教育小故事原创内容推送。