2 监控假说 （ The Monitor Hypothesis）
监控假说与习得---学得区别假说密切相关，它体现了―语言习得‖和―语言学习‖的内在关系。根据这个假设，语言习得与语言学习的作用各不相同。语言习得系统，即潜意识语言知识，才是真正的语言能力。而语言学得系统，即有意识的语言知识，只是在第二语言运用时起监控或编辑作用。这种监控功能既可能在语言输出（说、写）前也可能在其后。但是，它能否发挥作用还得依赖于三个先决条件：1）有足够的时间，即语言使用者必须要有足够的时间才能有效地选择和运用语法规则；2）注意语言形式，即语言使用者的注意力必须集中在所用语言的形式上，也就是说，必须考虑语言的正确性；3）知道规则，即语言使用者必须具有所学语言的语法概念及语言规则知识。
在口头表达时，人们一般注意的是说话的内容而不是形式，没有时间去考虑语法规则。因此，在说话时，如果过多地考虑使用语法监控，不断地纠正自己的语法错误，说起话来就会结结巴巴，妨碍交际进行。在书面表达时，情况就会好得多，因为作者有足够的时间推敲字句，斟酌语法。
3 输入假说（The Input Hypothesis）
输入假说也是克拉申语言习得理论的核心部分。他曾用一本专著论述他的这个假说。克拉申认为，只有当习得者接触到―可理解的语言输入‖（ comprehensive input ），即略高于他现有语言技能水平的第二语言输入，而他又能把注意力集中于对意义或对信息的理解而不是对形式的理解时，才能产生习得。这就是他著名的 i + 1 公式。i 代表习得者现有的水平, 1 代表略高于习得者现有水平的语言材料。根据克拉申的观点，这种 i + 1 的输入并不需要人们故意地去提供，只要习得者能理解输入，而他又有足够的量时，就自动地提供了这种输入。 克拉申认为，理想的输入应具备以下几个特点：
1）可理解性 （ comprehensibility）。理解输入的语言材料是语言习得的必要条件，不可理解的（ incomprehensible ） 输入对于习得者而言，只是一种噪音。
2）既有趣又有关 （ interesting and relevant ）。要使语言输入对语言的习得有利，必须对它的意义进行加工，输入的语言材料越有趣、越关联，学习者就会在不知不觉中习得语言。
3）非语法程序安排 （ not grammatically sequenced ）。语言习得关键是足量的可理解的输入。如果目的是―习得‖而不是―学得‖，按语法程序安排的教学不仅不必要，而且不可取。
4）要有足够的输入量。要习得新的语言结构，仅仅靠几道练习题、几篇短文是不够的，它需要连续不断地有内容有趣味的广泛阅读和大量的会话才能奏效。
4 情感过滤假说 （ The Affective Filter Hypothesis）。
这个假说认为，有大量的可理解输入的环境并不等于学生就可以学好目的语了，第二语言习得的过程还要受许多情感因素的影响。语言输入必须通过情感过滤才有可能变成语言―吸收‖（ intake ）。克拉申认为影响习得语言的情感因素是：1）动力。学生的学习目的是否明确，直接影响学习效果。目的明确则动力大，进
步快；反之，则收效甚微。2）性格。自信，性格外向，乐于置身于不熟悉的学习环境，自我感觉良好的学习者在学习中进步较快；3）情感状态。主要指焦虑和放松。焦虑感较强者，情感屏障高，获得的输入少；反之，则容易得到更多的输入。
5 自然顺序假说 （ The Natural Order Hypothesis）
这个假说认为，人们对语言结构知识的习得是按自然顺序进行的。例如，一些实验表明，在儿童和成人将英语作为第二语言学习时，掌握进行时先于掌握过去时，掌握名词复数先于掌握名词所有格 ‘s 等。克拉申认为，自然顺序假说并不要求人们按这种顺序来制定教学大纲。实际上，如果我们的目的是要习得某种语言能力的话，就有理由不按任何语法顺序来教学。
Krashen's Comprehension Hypothesis Model of L2 learning http://homepage.ntlworld.com/vivian.c/SLA/Krashen.htm
Combined model of acquisition and production
Evidence for the Input Hypothesis (chiefly Krashen 1985a) i) people speak to children acquiring their first language in special ways ii) people speak to L2 learners in special ways iii) L2 learners often go through an initial Silent Period iv) the comparative success of younger and older learners reflects provision of comprehensible input v) the more comprehensible input the greater the L2 proficiency vi) lack of comprehensible input delays language acquisition vii) teaching methods work according to the extent that they use comprehensible input viiiimmersion teaching is successful because it provides comprehensible ) input ix) bilingual programs succeed to the extent they provide comprehensible input
Academic reactions to Krashen
Krashen’s model lacks research evidence. As Cook (1993: 65-6) points out “it makes sense in its own terms but is not verifiable”.
Ellis (1990, p.57): 'the lucidity, simplicity, and explanatory power of Krashen's theory'.
Lightbown (1984, p.246): a combination of 'a linguistic theory (through its \(through its \filter\hypothesis), psychological learning theory (through its acquisition-learning hypothesis), discourse analysis and sociolinguistic theory (through both the comprehensible input hypothesis and the \
Mitchell & Myles (1998, p.126): 'The concepts of 'understanding' and 'noticing a gap' are not clearly operationalised, or consistently proposed; it is not clear how the learner's present state of knowledge ('i') is to be characterized, or indeed whether the 'i+1' formulation is intended to apply to all aspects of language, from lexis to phonology and syntax.'
Gregg (1984, p.94): 'each of Krashen's hypotheses is marked by serious flaws: indefinable or ill-defined terms, unmotivated constructs, lack of empirical content and thus of falsifiability, lack of explanatory power'
McLaughlin (1987, p.56): 'Krashen's theory fails at every juncture ... Krashen has not defined his terms with enough precision, the empirical basis of the theory is weak, and the theory is not clear in its predictions)
Ellis (1985, p.266): the Monitor Model 'poses serious theoretical problems regarding the validity of the 'acquisition-learning' distinction, the operation of Monitoring, and the explanation of variability in language-learner language'。
The Natural Approach (Krashen & Terrell, 1983; Terrell et al, 1997)
General premises
1. The goal is 'the ability to communicate with native speakers of the target language'
2. Comprehension precedes production – the Silent Period 3. Production 'emerges'
4. Acquisition activities are central, though some Monitoring may be useful for some people sometimes
5. Lower the Affective Filter: they won't learn if their affective
barrier is too high
6. Speech emerges in stages. Terrell et al 1997
7. Group work encourages speech. Terrell et al 1997
8. Speech emergence is characterized by grammatical errors. Terrell et al 1997
Techniques (all acquisition activities) a) Affective-Humanistic activities
dialogues – short and useful - 'open' dialogues interviews – pairwork on personal information personal charts and tables
preference ranking – opinion polls on favourite activities etc revealing information about yourself – e.g. what I had for breakfast
activating the imagination – e.g. give Napoleon advice about his Russian campaign
b) Problem-solving activities
task and series – e.g. components of an activity such as washing the car
charts, graphs, maps – e.g. busfares, finding the way
developing speech for particular occasions – e.g. What do you say if …
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c) Games, e.g. What is strange about … a bird swimming?'
d) Content activities, e.g. academic subject matter such as maths.
Some anti-Krashen opinions from California, --taken from KrashenBurn (see end)
Alice Callaghan (Episcopal priest), ?...a parasite on the backs of poor Latino children.‘
Isaac Cubillos, editor of Latino Beat ?...more than 2.5-million kids statewide have not made it as a result of bilingual education. What an atrocious situation, and Krashen helped create this.\
Isaac Cubillos, editor of Latino Beat, ?I discovered that Dr. Krashen has done no research. It is purely a theory. There is no test data, there are no schools where it's been proved, and it's based on thin air.‘
Christine Rossell \He will say anything to win over a room.\
David Tokofsky, \promoted from assistant principal to principal, or from teacher to bilingual coordinator, or from regional supe to district supe: By chanting the Mantra of 'Rama, Rama, Krashen, Krashen, Rama, Rama.'
One stunned non-educator in the audience: \impromptu
receiving line formed of teachers lining up for a chance to touch their guru, their Pied Piper. It was eery. It was the Church of Krashen.\
Krashen's own website: http://www.sdkrashen.com/
Long（1996）提出了互动假说（Interaction Hypothesis）。他认为会话中的互动能促进学习者语言能力的发展，而不仅仅是练习某些语言特征。意义协商(negotiation of meaning)会使谈话中的本族语者或语言能力较高的一方对非本族语者或语言能力较低的一方进行纠正或指导，从而引发互动，这种互动利于习得，因为它把输入、学习者内在能力（尤其是有选择的注意）和输出
有机地结合起来了。http://l2china.com/Show.Asp?ID=555
互动假说支撑下的计算机媒介交流语言学习
The Interaction Hypothesis suggests (Ellis，2003：P 80):
(1) that when interactional modifications lead to comprehensible input via the decomposition and segmenting of input[,] acquisition is facilitated; (2) that when learners receive feedback, acquisition is facilitated; and (3) that when learners are pushed to reformulate their own utterances, acquisition is promoted.
互动假说(interaction hypothesis)是Long根据Krashen的可理解性输入假说(comprehensible input hypothesis)提出的。Krashen认为可理解性输入是自发性的;Long的互动假说在认同Krashen的可理解性输入是语言习得的必要条件的同时,特别强调了意义协商(negotiation of meaning)对语言学习的促进作用。这一假说最初来源于对母语交谈者如何在交际中修正错误的研究和Hatch的主要观点,即学习者不是利用已有的在交际中获得的知识来学习第二语言,而是在交际的过程中学习第二语言。 Long还认为,“双向交际”(two-way communication)比“单向交际”(one-way communication)更有利于语言习得,因为在双向交际中,当一方无法理解另一方的话语时,会随时告知对方,这将促使双方进行意义协商和互动调整。互动调整有三种方式:理解核实(comprehension check)、确认核实(confirmation check)和澄清请求(clarification request)。 More Long 认为话语修正(如理解核查, 确认核查, 澄清要求)促进习得。Long（1996）认为, 协商促使学习者对他们的输出进行调整, 以使会话对方理解自己的话语,从而促进语言习得。
意义协商与二语习得