This document summarizes Krashen's input hypothesis and Swain's output hypothesis. The input hypothesis states that language acquisition occurs when learners understand language that is just beyond their current level. The output hypothesis argues that producing language through speaking and writing also contributes to acquisition by pushing learners to focus on expression. Both hypotheses complement each other, and a supportive learning environment, feedback, and engaging materials further help acquisition.

1. BUAP
Licenciatura abierta facultad de lenguas
Verónica E . Noriega Fernández

3. OUTPUT HYPOTHESIS
 “Output”, (1980) indicates the outcome of what the
student has learned.
 The Output hypothesis states that it is the action of
producing language, speaking and writing, which
develops part of the process of second language
learning (how proficient learners become). Swain
(1985)

4. Three functions of output
1) the noticing/triggering function
2) the hypothesis-testing function
3) the metalinguistic (reflective) function.
This means that the message needs to be conveyed
precisely, coherently, and appropriately. This form of
‘pushing’ students in terms of output is precisely the
same as that of Krashen’s comprehensible input notion
of i +1.

5. Figure 6: Input, intake and output

6. Krashen´s (1985) states that comprehensible input is the only
true way a learner has to acquire a second language.

7. INPUT
 Krashen´s input hypothesis which states that we
acquire the target language only when we understand
language (comprehensible input). In addition, in
order for learners to understand a language point, the
structure must be just "a little beyond" where students
are at the moment and they will use cultural baggage.

8. CONCLUSION
Input hypothesis Output hypothesis
 Krashen stressed that  Consequently, the feedback
comprehensible intput helps provided to the learner may
students acquire make input and output more
language.One important comprehensible. As Swain (1985)
principle of Krashen´s theory stated, production challenged
states that input should not learners to focus on the means
be grammatically sequenced of expression when they realize
as such sequencing is not it is necessary to enhance and
needed; thus, students would develop the target language
be able to understand every level, and it is just then, when
class and will never stay language output can contribute
behind. to language acquisition.

9. CONCLUSION
Both theories complement each other as all the elements
mentioned, strongly contribute to language acquisition.
One aspect to be taken into account is the positive
environment a teacher must create during his/her lesson as
it makes a difference in the students’ motivation and
interest in acquiring the second language.
Feedback plays an important role as well as correct
production, and interesting, appealing and meaningful
materials which may challenge and motivate learners.