Krashen’s Hypotheses of Second Language Acquisition
For decades, foreign language teachers wandered in a scientific abyss. Until 1983, there had been little real research dealing with the ways in which someone acquires a second language. Teachers mostly used the audiolingual classroom model that had been in place for the past twenty years (or, even worse, the literally ancient grammatical translation model that had been used by civilizations millennia old). Clearly, language teaching methodology was in a poor situation. In 1983, however, Krashen published the results of an unprecedented body of research and paved the way for a revolution in our field. His five-point hypothesis focused on the difference between the acquisition of and the learning of a second language. Krashen has his detractors, of course, not the least of whom are American school districts, which have been reluctant to implement his teachings. Most experts agree, however, that his ideas are the most meritorious of the theories in circulation now, and schools that refuse to incorporate them are doing their students a disservice.
The first of Krashen’s hypotheses is the learning-acquisition hypothesis, which differentiates the two titular terms. According to Krashen, “acquisition” refers to the implicit knowledge we have of a language, whereas “learning” refers to explicit knowledge about a language. Implicit knowledge refers to command of a language as if it were one’s native language; explicit knowledge is what we unfortunately gain in most foreign language classes. One good example of this in Spanish is the phrase “me llamo,” which literally means “I call myself” but is usually translated by Spanish teachers as “my name is.” While this is the most comprehensible translation for native English speakers, the syntax of the two expressions is too different for a beginner to use the Spanish properly. Possibly the most common error that new Spanish students commit is saying, “me llamo es…” (“es” meaning “is” in English). They assume that to say “my name is…” the Spanish word for “is” must be used and therefore commit this error. A native speaker, however, has only ever learned that to state his name, he must say “me llamo…” There is no error during transference between the two grammatical systems because an interlocutor’s implicit, acquired knowledge need never be transferred. The explicit, learned knowledge of a Spanish student has not ascended to the natural ability level of a native speaker; he must still make a conscious effort to communicate in his second language. This postulate is Krashen’s central idea and directly influences each of the four remaining hypotheses.
The second hypothesis is called the natural order hypothesis. This theory expresses that, during first- or second-language acquisition (though not necessarily second-language learning), the beginner will master grammatical structures in a specific,...