What is Comprehensible Input?
Teaching with Comprehensible Input (TCI) is a collection of approaches, techniques, and strategies for teaching language that prioritize the delivery of understandable and compelling messages in the target language. It is based heavily on the Comprehension Hypothesis of Stephen Krashen, which says that we acquire language when we understand what people tell us and what we read. In other words, there is no need for deliberate memorization of vocabulary or grammar rules. Instead, a firm knowledge of grammatical rules (a feel for correctness) and a large vocabulary gradually emerge as language acquirers get more comprehensible input (aural or written language that is understood) .