What is Comprehensible Input?
Stephen Krashen’s Comprehensible Input Theory is a cornerstone in second language acquisition research. The theory posits that learners acquire language by “taking in” and understanding language that is just a bit beyond their current level of competence (Krashen, 1985, p. 103).
An Illustrative Example
Consider a child who already understands the simple command "color your paper." When the phrase is modified to "color my paper," the child’s prior knowledge is leveraged to make new language input comprehensible. This subtle change builds on existing vocabulary to facilitate learning new structures and meanings (Sowers, 2000).
Input vs. Output
While the focus of comprehensible input is on absorbing language through exposure, Comprehensible Output—a concept advanced by Merrill K. Swain and Sharon Lapkin—emphasizes the importance of language production. Through activities like chants, songs, and structured dialogues, learners practice formulating responses, progressing from simple yes/no questions to more elaborate answers.
Learn More About Comprehensible OutputComprehensible Output encourages active use of language. By engaging in tasks that require speaking and writing, learners solidify their understanding and gain confidence in using new vocabulary and grammatical structures. Techniques include role-playing, peer discussions, and creative language games that complement input-based learning.
Why It Works
This approach leverages the brain's natural ability to integrate new information with existing knowledge. By exposing learners to slightly challenging input and encouraging active output, language acquisition becomes a natural, engaging process. The result is a more robust, intuitive command of the language over time.