In the course of his diary study dealing with communication strategies, the writer of this paper has found that the way of acquiring a language is not merely as simple as "understanding the message" as Krashen's Input Hypothesis (1985) claims. Swain's Comprehensible Output Hypothesis (1985) maintains that the development of a learner's communicative competence does not merely depend on comprehensible input: the learner's output has an independent and indispensible role to play. Swain's thesis has proved to be of relevance to the writer's experience as a self-directed learner. This paper discusses in detail the significance to language acquisition of pushing for comprehensible output. Three issues are discussed: (I) comprehensible output and negative input; (2) comprehensible output and incomprehensible output; (3) comprehensible output and comprehensible input.
A Review of Output Hypothesis in College English Teaching and Learning