input hypothesis krashen

The Input Hypothesis Model

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• Vivian Cook  

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The next three chapters look at the ways in which more general theories of second language acquisition have drawn on the type of syntactic evidence and the view of sequence of acquisition discussed in the previous chapter. This chapter is concerned with the Input Hypothesis proposed by Stephen Krashen. During the late 1970s Krashen put forward an account of SLA first known as the Monitor Model after its main claim about the role of monitoring in language learning (Krashen, 1979). In the early 1980s this was expanded into a broader-based model, described in Krashen (1981; 1982). The aspect of the model that became most developed was termed the Input Hypothesis , the title of Krashen’s last major theoretical book (Krashen, 1985a) and the name by which the model will be known here. From the beginning, Krashen’s ideas have been the subject of controversy. The discussion here does not follow all their ramifications but concentrates on the Input Hypothesis as put forward in Krashen (1985a), working back where necessary to earlier formulations. Initially the model will be presented as far as possible through the evidence and claims that he makes himself.

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© 1993 Vivian Cook

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Cook, V. (1993). The Input Hypothesis Model. In: Linguistics and Second Language Acquisition. Modern Linguistics Series. Palgrave, London. https://doi.org/10.1007/978-1-349-22853-9_3

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Introduction The Acquisition-Learning Hypothesis The Natural Order Hypothesis The Monitor Hypothesis The Input Hypothesis The Affective Filter Hypothesis Curriculum Design Conclusions Bibliography

  Introduction         The influence of Stephen Krashen on language education research and practice is undeniable.  First introduced over 20 years ago, his theories are still debated today.  In 1983, he published The Natural Approach with Tracy Terrell, which combined a comprehensive second language acquisition theory with a curriculum for language classrooms.  The influence of Natural Approach can be seen especially in current EFL textbooks and teachers resource books such as The Lexical Approach (Lewis, 1993).  Krashen’s theories on second language acquisition have also had a huge impact on education in the state of California, starting in 1981 with his contribution to Schooling and language minority students: A theoretical framework by the California State Department of Education (Krashen 1981).  Today his influence can be seen most prominently in the debate about bilingual education and perhaps less explicitly in language education policy:  The BCLAD/CLAD teacher assessment tests define the pedagogical factors affecting first and second language development in exactly the same terms used in Krashen’s Monitor Model (California Commission on Teacher Credentialing, 1998).         As advertised, The Natural Approach is very appealing – who wouldn’t want to learn a language the natural way, and what language teacher doesn’t think about what kind of input to provide for students.  However, upon closer examination of Krashen’s hypotheses and Terrell’s methods, they fail to provide the goods for a workable system.  In fact, within the covers of “The Natural Approach”, the weaknesses that other authors criticize can be seen playing themselves out into proof of the failure of Krashen’s model.  In addition to reviewing what other authors have written about Krashen’s hypotheses, I will attempt to directly address what I consider to be some of the implications for ES/FL teaching today by drawing on my own experience in the classroom as a teacher and a student of language.  Rather than use Krashen’s own label, which is to call his ideas simply “second language acquisition theory”, I will adopt McLaughlin’s terminology (1987) and refer to them collectively as “the Monitor Model”.  This is distinct from “the Monitor Hypothesis”, which is the fourth of Krashen’s five hypotheses. The Acquisition-Learning Hypothesis         First is the Acquisition-Learning Hypothesis, which makes a distinction between “acquisition,” which he defines as developing competence by using language for “real communication” and “learning.” which he defines as “knowing about” or “formal knowledge” of a language (p.26).  This hypothesis is presented largely as common sense: Krashen only draws on only one set of references from Roger Brown in the early 1970’s.  He claims that Brown’s research on first language acquisition showed that parents tend to correct the content of children’s speech rather than their grammar.  He compares it with several other authors’ distinction of “implicit” and “explicit” learning but simply informs the reader that evidence will be presented later.         Gregg (1984) first notes that Krashen’s use of the Language Acquisition Device (LAD) gives it a much wider scope of operation than even Chomsky himself.  He intended it simply as a construct to describe the child’s initial state, which would therefore mean that it cannot apply to adult learners.  Drawing on his own experience of learning Japanese, Gregg contends that Krashen’s dogmatic insistence that “learning” can never become “acquisition” is quickly refuted by the experience of anyone who has internalized some of the grammar they have consciously memorized.  However, although it is not explicitly stated, Krashen’s emphasis seems to be that classroom learning does not lead to fluent, native-like speech.  Gregg’s account that his memorization of a verb conjugation chart was “error-free after a couple of days”(p.81) seems to go against this spirit.  The reader is left to speculate whether his proficiency in Japanese at the time was sufficient enough for him to engage in error-free conversations with the verbs from his chart.         McLaughlin (1987) begins his critique by pointing out that Krashen never adequately defines “acquisition”, “learning”, “conscious” and “subconscious”, and that without such clarification, it is very difficult to independently determine whether subjects are “learning” or “acquiring” language.  This is perhaps the first area that needs to be explained in attempting to utilize the Natural Approach.  If the classroom situation is hopeless for attaining proficiency, then it is probably best not to start.  As we will see in an analysis of the specific methods in the book, any attempt to recreate an environment suitable for “acquisition” is bound to be problematic.         Krashen’s conscious/unconscious learning distinction appeals to students and teachers in monolingual countries immediately.  In societies where there are few bilinguals, like the United States, many people have struggled to learn a foreign language at school, often unsuccessfully.  They see people who live in other countries as just having “picked up” their second language naturally in childhood.  The effort spent in studying and doing homework seems pointless when contrasted with the apparent ease that “natural” acquisition presents.  This feeling is not lost on teachers: without a theoretical basis for the methods, given any perceived slow progress of their students, they would feel that they have no choice but to be open to any new ideas         Taking a broad interpretation of this hypothesis, the main intent seems to be to convey how grammar study (learning) is less effective than simple exposure (acquisition).  This is something that very few researchers seem to doubt, and recent findings in the analysis of right hemisphere trauma indicate a clear separation of the facilities for interpreting context-independent sentences from context-dependent utterances (Paradis, 1998).  However, when called upon to clarify, Krashen takes the somewhat less defensible position that the two are completely unrelated and that grammar study has no place in language learning (Krashen 1993a, 1993b).  As several authors have shown (Gregg 1984, McLaughlin 1987, and Lightbown & Pienemann 1993, for a direct counter-argument to Krashen 1993a) there are countless examples of how grammar study can be of great benefit to students learning by some sort of communicative method. The Natural Order Hypothesis         The second hypothesis is simply that grammatical structures are learned in a predictable order.  Once again this is based on first language acquisition research done by Roger Brown, as well as that of Jill and Peter de Villiers.  These studies found striking similarities in the order in which children acquired certain grammatical morphemes.  Krashen cites a series of studies by Dulay and Burt which show that a group of Spanish speaking and a group of Chinese speaking children learning English as a second language also exhibited a “natural” order for grammatical morphemes which did not differ between the two groups.  A rather lengthy end-note directs readers to further research in first and second language acquisition, but somewhat undercuts the basic hypothesis by showing limitations to the concept of an order of acquisition.         Gregg argues that Krashen has no basis for separating grammatical morphemes from, for example, phonology.  Although Krashen only briefly mentions the existence of other parallel “streams” of acquisition in The Natural Approach, their very existence rules out any order that might be used in instruction.  The basic idea of a simple linear order of acquisition is extremely unlikely, Gregg reminds us.  In addition, if there are individual differences then the hypothesis is not provable, falsifiable, and in the end, not useful.         McLaughlin points out the methodological problems with Dulay and Burt’s 1974 study, and cites a study by Hakuta and Cancino (1977, cited in McLaughlin, 1987, p.32) which found that the complexity of a morpheme depended on the learner’s native language.  The difference between the experience of a speaker of a Germanic language studying English with that of an Asian language studying English is a clear indication of the relevance of this finding.  The contradictions for planning curriculum are immediately evident.  Having just discredited grammar study in the Acquisition-Learning Hypothesis, Krashen suddenly proposes that second language learners should follow the “natural” order of acquisition for grammatical morphemes.  The teacher is first instructed to create a natural environment for the learner but then, in trying to create a curriculum, they are instructed to base it on grammar.  As described below in an analysis of the actual classroom methods presented in the Natural Approach, attempting to put these conflicting theories into practice is very problematic.         When one examines this hypothesis in terms of comprehension and production, its insufficiencies become even more apparent.  Many of the studies of order of acquisition, especially those in first language acquisition, are based on production.  McLaughlin also points out that “correct usage” is not monolithic – even for grammatical morphemes, correct usage in one situation does not guarantee as correct usage in another (p.33).  In this sense, the term “acquisition” becomes very unclear, even when not applying Krashen’s definition.  Is a structure “acquired” when there are no mistakes in comprehension?  Or is it acquired when there is a certain level of accuracy in production?  First language acquisition is very closely linked to the cognitive development of infants, but second language learners have most of these facilities present, even as children.  Further, even if some weak form of natural order exists for any learners who are speakers of a given language, learning in a given environment, it is not clear that the order is the same for comprehension and production.  If these two orders differ, it is not clear how they would interact. The Monitor Hypothesis The role of conscious learning is defined in this somewhat negative hypothesis: The only role that such “learned” competence can have is an editor on what is produced.  Output is checked and repaired, after it has been produced, by the explicit knowledge the learner has gained through grammar study.  The implication is that the use of this Monitor should be discouraged and that production should be left up to some instinct that has been formed by “acquisition”.  Using the Monitor, speech is halting since it only can check what has been produced, but Monitor-free speech is much more instinctive and less contrived.  However, he later describes cases of using the Monitor efficiently (p. 32) to eliminate errors on “easy” rules.  This hypothesis presents very little in the way of supportive evidence:  Krashen cites several studies by Bialystok alone and with Frohlich as “confirming evidence” (p.31) and several of his own studies on the difficulty of confirming acquisition of grammar.         Perhaps Krashen’s recognition of this factor was indeed a step forward – language learners and teachers everywhere know the feeling that the harder they try to make a correct sentence, the worse it comes out.  However, he seems to draw the lines around it a bit too closely.  Gregg points (p.84) out that by restricting monitor use to “learned” grammar and only in production, Krashen in effect makes the Acquisition-Learning Hypothesis and the Monitor Hypothesis contradictory.  Gregg also points out that the restricting learning to the role of editing production completely ignores comprehension (p.82).  Explicitly learned grammar can obviously play a crucial role in understanding speech.         McLaughlin gives a thorough dissection of the hypothesis, showing that Krashen has never demonstrated the operation of the Monitor in his own or any other research.  Even the further qualification that it only works on discrete-point tests on one grammar rule at a time failed to produce evidence of operation.  Only one study (Seliger, cited on p.26) was able to find narrow conditions for its operation, and even there the conclusion was that it was not representative of the conscious knowledge of grammar.  He goes on to point out how difficult it is to determine if one is consciously employing a rule, and that such conscious editing actually interferes with performance.  But his most convincing argument is the existence of learners who have taught themselves a language with very little contact with native speakers.  These people are perhaps rare on the campuses of U.S. universities, but it is quite undeniable that they exist.         The role that explicitly learned grammar and incidentally acquired exposure have in forming sentences is far from clear.  Watching intermediate students practice using recasts is certainly convincing evidence that something like the Monitor is at work: even without outside correction, they can eliminate the errors in a target sentence or expression of their own ideas after several tries.  However, psycholinguists have yet to determine just what goes into sentence processing and bilingual memory.  In a later paper (Krashen 1991), he tried to show that high school students, despite applying spelling rules they knew explicitly, performed worse than college students who did not remember such rules.  He failed to address not only the relevance of this study to the ability to communicate in a language, but also the possibility that whether they remembered the rules or not, the college students probably did know the rules consciously at some point, which again violates the Learning-Acquisition Hypothesis. The Input Hypothesis         Here Krashen explains how successful “acquisition” occurs:  by simply understanding input that is a little beyond the learner’s present “level” – he defined that present “level” as i and the ideal level of input as i +1.  In the development of oral fluency, unknown words and grammar are deduced through the use of context (both situational and discursive), rather than through direct instruction.  Krashen has several areas which he draws on for proof of the Input Hypothesis.  One is the speech that parents use when talking to children (caretaker speech), which he says is vital in first language acquisition (p.34).  He also illustrates how good teachers tune their speech to their students’ level, and how when talking to each other, second language learners adjust their speech in order to communicate.  This hypothesis is also supported by the fact that often the first second language utterances of adult learners are very similar to those of infants in their first language.  However it is the results of methods such as Asher’s Total Physical Response that provide the most convincing evidence.  This method was shown to be far superior to audiolingual, grammar-translation or other approaches, producing what Krashen calls “nearly five times the [normal] acquisition rate.”         Gregg spends substantial time on this particular hypothesis, because, while it seems to be the core of the model, it is simply an uncontroversial observation with no process described and no proof provided.  He brings up the very salient point that perhaps practice does indeed also have something to do with second language acquisition, pointing out that monitoring could be used as a source of correct utterances (p. 87).  He also cites several studies that shed some doubt on the connection between caretaker speech in first language acquisition and simplified input in second language acquisition.         McLaughlin also gives careful and thorough consideration to this part of Krashen’s model.  He addresses each of the ten lines of evidence that Krashen presents, arguing that it is not sufficient to simply say that certain phenomenon can be viewed from the perspective of the Input Hypothesis.  The concept of a learner’s “level” is extremely difficult to define, just as the idea of i +1 is (p.37).  Further, there are many structures such as passives and yes/no questions that cannot be learned through context.  Also, there is no evidence that a learner has to fully comprehend an utterance for it to aid in acquisition.  Some of the first words that children and second language learners produce are formulaic expressions that are not fully understood initially.  Finally McLaughlin points out that Krashen simply ignores other internal factors such as motivation and the importance of producing language for interaction.         This hypothesis is perhaps the most appealing part of Krashen’s model for the language learner as well as the teacher.  He makes use of the gap between comprehension and production that everyone feels, enticing us with the hope of instant benefits if we just get the input tuned to the right level.  One of Krashen’s cleverest catch-alls is that other methods of teaching appear to work at times because they inadvertently provide this input.  But the disappointment is that he never gives any convincing idea as to how it works.  In the classroom a teacher can see when the students don’t understand and can simplify his or her speech to the point where they do.  Krashen would have the teacher think that this was all that is necessary, and it is just a matter of time before the students are able to express themselves freely.  However, Ellis (1992) points out that even as of his 1985 work (Krashen 1985), he still had not provided a single study that demonstrated the Input Hypothesis.  Over extended periods of time students do learn to understand more and even how to speak, but it often seems to take much longer than Krashen implies, indicating that there are perhaps many more factors involved.  More importantly, even given this beginning of i, and the goal of i + 1, indefinable as they are, the reader is given no indication of how to proceed.  As shown above the Natural Order Hypothesis holds no answers, especially as to how comprehension progresses.  In an indication of a direction that should be explored, Ellis’s exploratory study (ibid.) showed that it is the effort involved in attempting to understand input rather than simple comprehension that fuels acquisition. The Affective Filter Hypothesis         This concept receives the briefest treatment in “The Natural Approach”.  Krashen simply states that “attitudinal variables relate directly to language acquisition but not language learning.”  He cites several studies that examine the link between motivation and self-image, arguing that an “integrative” motivation (the learner want to “be like” the native speakers of a language) is necessary.  He postulates an “affective filter” that acts before the Language Acquisition Device and restricts the desire to seek input if the learner does not have such motivation.  Krashen also says that at puberty, this filter increases dramatically in strength.         Gregg notes several problems with this hypothesis as well.  Among others, Krashen seems to indicate that perhaps the affective filter is associated with the emotional upheaval and hypersensitivity of puberty, but Gregg notes that this would indicate that the filter would slowly disappear in adulthood, which Krashen does not allow for (p.92).  He also remarks on several operational details, such as the fact that simply not being unmotivated would be the same as being highly motivated in this hypothesis – neither is the negative state of being unmotivated.  Also, he questions how this filter would selectively choose certain “parts of a language” to reject (p.94).         McLaughlin argues much along the same lines as Gregg and points out that adolescents often acquire languages faster than younger, monitor-free children (p.29).  He concludes that while affective variables certainly play a critical role in acquisition, there is no need to theorize a filter like Krashen’s.         Again, the teacher in the classroom is enticed by this hypothesis because of the obvious effects of self-confidence and motivation.  However, Krashen seems to imply that teaching children, who don’t have this filter, is somehow easier, since “given sufficient exposure, most children reach native-like levels of competence in second languages” (p.47).  This obviously completely ignores the demanding situations that face language minority children in the U.S. every day.  A simplification into a one page “hypothesis” gives teachers the idea that these problems are easily solved and fluency is just a matter of following this path.  As Gregg and McLaughlin point out, however, trying to put these ideas into practice, one quickly runs into problems. Curriculum Design         The educational implications of Krashen’s theories become more apparent in the remainder of the book, where he and Terrell lay out the specific methods that make use of the Monitor Model.  These ideas are based on Terrell’s earlier work (Terrell, 1977) but have been expanded into a full curriculum.  The authors qualify this collection somewhat by saying that teachers can use all or part of the Natural Approach, depending on how it fits into their classroom.         This freedom, combined with the thoroughness of their curriculum, make the Natural Approach very attractive.  In fact, the guidelines they set out at the beginning– communication is the primary goal, comprehension preceding production, production simply emerge, acquisition activities are central, and the affective filter should be lowered (p. 58-60) – are without question, excellent guidelines for any language classroom.  The compilation of topics and situations (p.67-70) which make up their curriculum are a good, broad overview of many of the things that students who study by grammar translation or audiolingual methods do not get.  The list of suggested rules (p.74) is notable in its departure from previous methods with its insistence on target language input but its allowance for partial, non-grammatical or even L1 responses.         Outside of these areas, application of the suggestions run into some difficulty.  Three general communicative goals of being able to express personal identification, experiences and opinions (p.73) are presented, but there is no theoretical background.  The Natural Approach contains ample guidance and resources for the beginner levels, with methods for introducing basic vocabulary and situations in a way that keeps students involved.  It also has very viable techniques for more advanced and self-confident classes who will be stimulated by the imaginative situational practice (starting on p.101).  However, teachers of the broad middle range of students who have gotten a grip on basic vocabulary but are still struggling with sentence and question production are left with conflicting advice.         Once beyond one-word answers to questions, the Natural Approach ventures out onto thin ice by suggesting elicited productions.  These take the form of open-ended sentences, open dialogs and even prefabricated patterns (p.84).  These formats necessarily involve explicit use of grammar, which violates every hypothesis of the Monitor Model.  The authors write this off as training for optimal Monitor use (p.71, 142), despite Krashen’s promotion of “Monitor-free” production.  Even if a teacher were to set off in this direction and begin to introduce a “structure of the day” (p. 72), once again there is no theoretical basis for what to choose.  Perhaps the most glaring omission is the lack of any reference to the Natural Order Hypothesis, which as noted previously, contained no realistically usable information for designing curriculum.         Judging from the emphasis on exposure in the Natural Approach and the pattern of Krashen’s later publications, which focused on the Input Hypothesis, the solution to curriculum problems seems to be massive listening.  However, as noted before, other than i + 1, there is no theoretical basis for overall curriculum design regarding comprehension.  Once again, the teacher is forced to rely on a somewhat dubious “order of acquisition”, which is based on production anyway.  Further, the link from exposure to production targets is tenuous at best.  Consider the dialog presented on p.87: . . . to the question What is the man doing in this picture? the students may reply run.  The instructor expands the answer.  Yes, that’s right, he’s running.

Krashen's Second Language Acquisition Theory

Input Hypothesis

The Input Hypothesis is part of a group of 5 hypotheses related to Second Language Acquisition developed by the linguist Stephen Krashen.

According to this Hypothesis, the results of the acquisition of a second language are related to the input that the acquirer receives/is exposed to. However, this input has to be understood (comprehensible input), and it is from this precept that Krashen established that in order for the acquirer to achieve results, the level of language he is exposed to must follow the i + 1 standard where i means the Acquirer’s actual competence in the language and +1 means a bit further. That is, the students should always be exposed to a slightly more advanced level of understandable input so that they can achieve ever more fluency in the Second Language.

Based on how children acquire their first language and the caretaker speech (a simple language used with children for them to understand), Krashen proposed something similar to be worked on with adults: the teacher-talk, the Foreigner-talk, and the Interlanguage- talk, also known as Simple codes.

The “Teacher-talk” is the classroom language that accompanies exercises, the language of explanations in the second language and in some foreign language classrooms, and the language of classroom management. “Interlanguage talk” is simply the speech of other second language acquirers, often that of the foreign student peer group and “Foreigner-talk” may be of two kinds. The term has been used to describe native speakers’ imitations of second language speech or, rather, their acquisition of aspects of this interlanguage. (Krashen, 1981,p. 121)

According to him, these are the 3 simple codes that are part of the process of acquiring a language. The teacher-talk promotes more input than the exercises a teacher may do in classes. So, the language itself used in the teacher speech is a way of promoting comprehensible input, that is if the teacher takes into account that the language, he may use, must be into the patterns of the formula i+1 cited above. The theorist also mentions the interlanguage-talk and the foreigner-talk that provide the students with the input they need during the classes and outside the school environment.

In sum, this hypothesis says that we acquire language through a unique way, comprehending or receiving comprehensible input and that this comprehension follows a natural order, from i to i+1. So, an input is an essential ingredient in Language Acquisition and is related to other 4 Hypotheses.

By M. A. M. Júnior

KRASHEN, Stephen. Second Language Acquisition and Second Language Learning . University of Southern California. Available on:  <http://www.sdkrashen.com/content/books/sl_acquisition_and_learning.pdf>  Access on

KRASHEN, Stephen D.  Issues and Implications . In: The Input Hypothesis. 1985. p. 1-32. Available on: < https://www.uio.no/studier/emner/hf/iln/LING4140/h08/The%20Input%20Hypothesis.pdf&gt ; Acess on

Stephen Krashen . In: Wikipedia, the free encyclopedia. Available in: < https://en.wikipedia.org/wiki/Input_hypothesis#cite_note-Krashen2003-3&gt ; Access on Nov 30, 2018.

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The input hypothesis is a hypothesis in second language acquisition developed by Stephen Krashen, which states that a language learner gains the most benefit from receiving linguistic input that is just beyond his or her current interlanguage, or level of grammatical understanding. This type of input is known as comprehensible input or "i + 1," where "i" refers to the learner's interlanguage. According to Krashen, comprehensible input is most likely to be gained from interacting with another speaker of the language.

In some respects, the input hypothesis is fairly intuitive. Someone who understands only a few basic phrases of Chinese will not derive much benefit from listening to a scientific discourse in Chinese since it will be incomprehensible. Likewise, someone who is nearly fluent in Italian will not gain much grammatical knowledge from a child's picture book, because it will not introduce any new grammatical features.

Krashen, however, draws on more complex theories of second language acquisition to make his claim. The interlanguage hypothesis states that learners acquire the grammatical features of a language in a predictable order, and that at any given time the learner has an internally consistent grammatical framework known as the interlanguage. As the learner progresses, the interlanguage becomes increasingly similar to the target language 's actual grammar. The input hypothesis states that input one stage closer to the target language — or i + 1 input — helps the learner acquire the next set of grammatical features. It is not enough, however, for a learner to receive comprehensible input passively; he or she must then analyze the new data in order to move the interlanguage forward.

The input hypothesis states that the best way for learners to gather comprehensible input is through a sort of trial-and-error process of communication. The learner seeks out conversation partners, who modify their speech until it becomes comprehensible to the learner. This process can be aided by nonverbal communication, such as by gestures and by feedback from the learner. When the process is successful, the learner's interlanguage grows to accommodate new grammatical features that he or she has observed.

Krashen claims that output, or speech production, has little to no relevance in second language acquisition . Many other researchers have criticized this position, however, saying that more advanced language learning and syntactic processing have to come through the trial-and-error process not only of comprehending, but also of speaking. Language output allows the speaker to test out his or her grammatical hypotheses and modify them if communication is not successful.

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Input hypothesis.

By Benjamin Niedzielski on January 14, 2020

The idea that language learners need exposure to the language (or “input”) to make progress in the target language is neither surprising nor new.  What is surprising is what the best type of input might be.

Linguist Stephen Krashen (a UCLA graduate) has written about this in his “Input Hypothesis”. Krashen supports an i+1 input approach for second language learners, meaning the best input is only one level above the learner’s level to maximize comprehension . This allows students to make use of context to understand unknown words or phrases, as native speakers do.  

Krashen’s hypothesis is not accepted by everyone (see Zafar 2009 and Liu 2015 ), as it is difficult or impossible to test. In addition, it is unclear what exactly i+1 input looks like, as it varies from case to case. Still, the general idea is attractive even if the details are disputed.

Most modern language classes that I have taken across the United States have followed the Input Hypothesis (at least partially). Classes teach grammar and vocabulary step by step. Listening and reading activities contain mostly words that are already known. This lets students focus on new concepts without being overwhelmed, and build on what they have mastered.

However, no two students are at the same level in a language. Some will have more exposure outside of the classroom. Others may have competencies in a related language that puts them above their peers (knowing French helps learn Italian for instance). In larger classes, providing i+1 input to each student individually may be impossible to achieve.

Technology, however, can allow teachers and students to bridge this gap. For many languages, there are large amounts of “input” at different levels available online. An instructor can find (or create) sites at different levels and ask students to choose something to read or listen to for a certain amount of time, allowing students to find their own i+1 input from an approved list. Instructors can guide students by saying that what students choose must contain new words but be understandable without a dictionary.

Examples of these kind of resources are NHK News Web Easy or Wasabi’s Fairy Tales and Short Stories with Easy Japanese , with reading practice at different levels. One of my personal favorites was a German class where we used iPods to find and listen to German music or podcasts, such as like Deutsche Welle’s Langsam gesprochene Nachrichten (Slowly Spoken News), that we students liked and could easily understand.

Activities such as these allow students the flexibility to seek out their own i+1 input in an instructor curated fashion.  They get more practice with a language outside of the classroom, and can find materials that meet their own needs and interests. 

Whether or not the Input Hypothesis is correct, giving students these opportunities is a great way to engage them effectively with a language and culture.

Image: language-2345801_1920.jpg . Image is used under the Pixabay License .( https://pixabay.com/photos/language-learning-books-education-2345801/ ) 

• Deutsche Welle. “Langsam gesprochene Nachrichten“. https://www.dw.com/de/21102019-langsam-gesprochene-nachrichten/a-50911528
• Krashen, S. (1982). Principles and Practice in Second Language Acquisition. Oxford: Pergamon Press.
• Krashen, S. (1985). The Input Hypothesis: Issues and Implications. Harlow: Longman.
• NHK News Web Easy: https://www3.nhk.or.jp/news/easy/
• Liu 2015: http://jehdnet.com/journals/jehd/Vol_4_No_4_December_2015/16.pdf
• Teaching English. “Comprehensible Input”. https://www.teachingenglish.org.uk/article/comprehensible-input . Accessed Nov. 5, 2019.
• Wasabi’s Fairy Tales and Short Stories with Easy Japanese: https://www.wasabi-jpn.com/japanese-lessons/fairy-tales-and-short-stories-with-easy-japanese/
• Zafar 2009: https://pdfs.semanticscholar.org/39ee/7d69dae91b26dcffd84d718eb93f6d7795a4.pdf

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Stephen Krashen’s Five Hypotheses of Second Language Acquisition

Unsplash Monica Melton

Interested in learning more about linguistics and linguists ? Read this way.

What is linguistics? Linguistics is the scientific study of language that involves the analysis of language rules, language meaning, and language context. In other words, linguistics is the study of how a language is formed and how it works.

A person who studies linguistics is called a linguist . A linguist doesn't necessarily have to learn different languages because they’re more interested in learning the structures of languages. Noam Chomsky and Dr. Stephen Krashen are two of the world’s most famous linguists.

Dr. Stephen D. Krashen facilitated research in second-language acquisition , bilingual education, and in reading. He believes that language acquisition requires “meaningful interaction with the target language.”

Dr. Krashen also theorized that there are 5 hypotheses to second language acquisition , which have been very influential in the field of second language research and teaching

Let’s take a look at these hypotheses. Who knows, maybe you’ve applied one or all of them in your language learning journey!

1. Acquisition-Learning Hypothesis

The Acquisition-Learning Hypothesis states that there is a distinction between language acquisition and language learning. In language acquisition, the student acquires language unconsciously . This is similar to when a child picks up their first language. On the other hand, language learning happens when the student is consciously discovering and learning the rules and grammatical structures of the language.

2. Monitor Hypothesis

Monitor Hypothesis states that the learner is consciously learning the grammar rules and functions of a language rather than its meaning. This theory focuses more on the correctness of the language . To use the Monitor Hypothesis properly, three standards must be met:

• The acquirer must know the rules of the language.
• The acquirer must concentrate on the exact form of the language.
• The acquirer must set aside some time to review and apply the language rules in a conversation. Although this is a tricky one, because in regular conversations there’s hardly enough time to ensure correctness of the language.

3. Natural Order Hypothesis

Natural Order Hypothesis is based on the finding that language learners learn grammatical structures in a fixed and universal way . There is a sense of predictability to this kind of learning, which is similar to how a speaker learns their first language.

4. Input Hypothesis

Input Hypothesis places more emphasis on the acquisition of the second language. This theory is more concerned about how the language is acquired rather than learned.

Moreover, the Input Hypothesis states that the learner naturally develops language as soon as the student receives interesting and fun information .

5. Affective Filter Hypothesis

In Affective Filter, language acquisition can be affected by emotional factors. If the affective filter is higher, then the student is less likely to learn the language. Therefore, the learning environment for the student must be positive and stress-free so that the student is open for input.

Language acquisition is a subconscious process. Usually, language acquirers are aware that they’re using the language for communication but are unaware that they are acquiring the language.

Language acquirers also are unaware of the rules of the language they are acquiring. Instead, language acquirers feel a sense of correctness, when the sentence sounds and feels right. Strange right? But it is also quite fascinating.

Acquiring a language is a tedious process. It can seem more like a chore, a game of should I learn today or should I just do something else? Sigh

But Dr. Krashen’s language acquisition theories might be onto something, don’t you think? Learning a language should be fun and in some way it should happen naturally. Try to engage in meaningful interactions like reading exciting stories and relevant news articles, even talking with friends and family in a different language. Indulge in interesting and easy to understand language activities, and by then you might already have slowly started acquiring your target language!

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The Input Hypothesis: Definition and Criticism

January 22, 2018, 9:00 am

Stephen Krashen is a linguist and educator who proposed the Monitor Model, a theory of second language acquisition, in Principles and practice in second language acquisition as published in 1982. According to the Monitor Model, five hypotheses account for the acquisition of a second language:

• Acquisition-learning hypothesis
• Natural order hypothesis
• Monitor hypothesis
• Input hypothesis
• Affective filter hypothesis

However, despite the popularity and influence of the Monitor Model, the five hypotheses are not without criticism. The following sections offer a description of the fourth hypothesis of the theory, the input hypothesis, as well as the major criticism by other linguistics and educators surrounding the hypothesis.

Definition of the Input Hypothesis

The fourth hypothesis, the input hypothesis, which applies only to language acquisition and not to language learning, posits the process that allows second language learners to move through the predictable sequence of the acquisition of grammatical structures predicted by the natural order hypothesis. According to the input hypothesis, second language learners require comprehensible input, represented by i+1 , to move from the current level of acquisition, represented by i , to the next level of acquisition. Comprehensible input is input that contains a structure that is “a little beyond” the current understanding—with understanding defined as understanding of meaning rather than understanding of form—of the language learner.

Second language acquisition, therefore, occurs through exposure to comprehensible input, a hypothesis which further negates the need for explicit instruction learning. The input hypothesis also presupposes an innate language acquisition device, the part of the brain responsible for language acquisition, that allows for the exposure to comprehensible input to result in language acquisition, the same language acquisition device posited by the acquisition-learning hypothesis. However, as Krashen cautions, like the time, focus, and knowledge required by the Monitor, comprehensible input is necessary but not sufficient for second language acquisition.

Criticism of the Input Hypothesis

Like for the acquisition-learning hypothesis, the first critique of the input hypothesis surrounds the lack of a clear definition of comprehensible input; Krashen never sufficiently explains the values of i or i+1 . As Gass et al. argue, the vagueness of the term means that i+1 could equal “one token, two tokens, 777 tokens”; in other words, sufficient comprehensible input could embody any quantity.

More importantly, the input hypothesis focuses solely on comprehensible input as necessary, although not sufficient, for second language acquisition to the neglect of any possible importance of output. The output hypothesis as proposed by Merrill Swain seeks to rectify the assumed inadequacies of the input hypothesis by positing that language acquisition and learning may also occur through the production of language. According to Swain who attempts to hypothesize a loop between input and output, output allows second language learners to identify gaps in their linguistic knowledge and subsequently attend to relevant input. Therefore, without minimizing the importance of input, the output hypothesis complements and addresses the insufficiencies of the input hypothesis by addressing the importance of the production of language for second language acquisition.

Thus, despite the influence of the Monitor Model in the field of second language learning and acquisition, the input hypothesis, the fourth hypothesis of the theory, has not been without criticism as evidenced by the critiques offered by other linguists and educators in the field.

Gass, Susan M. & Larry Selinker. 2008. Second language acquisition: An introductory course , 3rd edn. New York: Routledge. Krashen, Stephen D. 1982. Principles and practice in second language acquisition . Oxford: Pergamon. http://www.sdkrashen.com/Principles_and_Practice/Principles_and_Practice.pdf. Swain, Merrill. 1993. The output hypothesis: Just speaking and writing aren’t enough. The Canadian Modern Language Review 50(1). 158-164. Zafar, Manmay. 2009. Monitoring the ‘monitor’: A critique of Krashen’s five hypotheses. Dhaka University Journal of Linguistics 2(4). 139-146.

input hypothesis language acquisition language learning monitor model

The Monitor Hypothesis: Definition and Criticism

The Affective Filter Hypothesis: Definition and Criticism