Krashen's 6 Hypotheses

Dr. B SaysIn her reflection Marguerite mentions how her students are apprehensive to produce spoken language.  She states that they are anxious about using the TL.  Language teachers and learners alike know that producing oral language can be a challenge but that it is a necessary part of learning a language.  Like Marguerite's students many language students may feel worried about the level of their language. This often prevents them from speaking or taking in the language at all.  In addition, many learners tend to monitor their use of the language too much, focusing more on accuracy than fluency which in turn prevents them from using the language in a communicative manner. In this section, we will look at the work of Stephen Krashen, specifically his 6 hypotheses on language acquisition, in order to better understand the challenges that might arise during the language learning process. 
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Some Questions'

CitationWhat are Krashen's Hypotheses?

Krashen's theory of second language acquisition consists of six main hypotheses:

  • the Acquisition-Learning hypothesis
  • the Monitor hypothesis
  • the Natural Order hypothesis
  • the Input hypothesis
  • the Affective Filter hypothesis
  • the Reading Hypothesis

How do Krashen's Hypotheses apply to the SL/FL classroom?

Explanation of Hypothesis

Application for Teaching

The Acquisition-Learning hypothesis
According to Krashen, there are two ways of developing language ability.  Acquisition involves the subconscious acceptance of knowledge where information is stored in the brain through the use of communication; this is the process used for developing native languages.  Learning, on the other hand, is the conscious acceptance of knowledge ‘about’ a language (i.e. the grammar or form). Krashen states that this is often the product of formal language instruction. 

According to this theory, the optimal way a language is learned is through natural communication.  As a second language teacher, the ideal is to create a situation wherein language is used in order to fulfill authentic purposes.  This is turn, will help students to ‘acquire’ the language instead of just ‘learning’ it.

The Monitor hypothesis
This hypothesis further explains how acquisition and learning are used; the acquisition system, initiates an utterance and the learning system ‘monitors’ the utterance to inspect and correct errors.  Krashen states that monitoring can make some contribution to the accuracy of an utterance but its use should be limited.  He suggests that the ‘monitor’ can sometimes act as a barrier as it forces the learner to slow down and focus more on accuracy as opposed to fluency.

As an SL teacher it will always be a challenge to strike a balance between encouraging accuracy and fluency in your students. This balance will depend on numerous variables including the language level of the students, the context of language use and the personal goals of each student.  This balance is also known as Communicative competency

The Natural Order hypothesis
According to Krashen, learners acquire parts of language in a predictable order.  For any given language, certain grammatical structures are acquired early while others are acquired later in the process.  This hypothesis suggests that this natural order of acquisition occurs independently of deliberate teaching and therefore teachers cannot change the order of a grammatical teaching sequence.

According to this hypothesis, teachers should be aware that certain structures of a language are easier to acquire than others and therefore language structures should be taught in an order that is conducive to learning. Teachers should start by introducing language concepts that are relatively easy for learners to acquire and then use scaffolding to introduce more difficult concepts.

The Input hypothesis
This hypothesis suggests that language acquisition occurs when learners receive messages that they can understand, a concept also known as comprehensible input.  However, Krashen also suggests that this comprehensible input should be one step beyond the learner’s current language ability, represented as i + 1, in order to allow learners to continue to progress with their language development.

This hypothesis highlights the importance of using the Target Language in the classroom.  The goal of any language program is for learners to be able to communicate effectively.  By providing as much comprehensible input as possible, especially in situations when learners are not exposed to the TL outside of the classroom, the teacher is able to create a more effective opportunity for language acquisition.

The Affective Filter hypothesis
According to Krashen one obstacle that manifests itself during language acquisition is the affective filter; that is a 'screen' that is influenced by emotional variables that can prevent learning.  This hypothetical filter does not impact acquisition directly but rather prevents input from reaching the language acquisition part of the brain.  According to Krashen the affective filter can be prompted by many different variables including anxiety, self-confidence, motivation and stress. 

In any aspect of education it is always important to create a safe, welcoming environment in which students can learn. In language education this may be especially important since in order to take in and produce language, learners need to feel that they are able to make mistakes and take risks.  This relates to directly to Krashen’s hypothesis of the affective filter.  To learn more about creating a positive classroom environment, click here.

The Reading Hypothesis
This hypothesis basically states that the more we read in a SL the greater our vocabulary will be.


It is important to involve reading in the language classroom to increase knowledge of the language and the way it is used in real-life contexts.

What do Krashen's Hypotheses look like in the classroom?

Look at the cartoon and decide which of Krashen's Hypotheses apply to this student. Explain your answers.


Test your knowledge of Krashen's Hypotheses with this quiz.



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