Dr. Stephen Krashen has for many decades articulated many important ideas based on evidence and research about educational issues related to reading and language learning. He has presented evidence that spelling, grammar, vocabulary, phonics, phonics awareness, and knowledge of text structure can be acquired and improved without explicit instruction or skill-building of any kind.
Krashen’s theory of language acquisition discusses that the human brain will naturally acquire the features of language in a predictable way. This order of acquisition cannot be altered by instruction. When teachers or instruction forces acquisition the students find themselves fighting with their own brains and find language learning frustrating and think they are not good at languages.
Students that learn language explicitly or through “skill building” are virtually unable to naturally produce language and rely on memorized rehearsed phrases in order to produce output.
Here he is speaking at KOTESOL in 2011.