Krashen theories

Acquisition theory seeks to quantify how and by what processes individuals acquire a second language. The predominant theory of second language acquisition was developed by the University of SouthernCalifornia’s Steven Krashen. Krashen is a specialist in language development and acquisition, and his influential theory is widely accepted in the language learning community.
Five Components ofSecond Language Acquisition Theory
There are five main components of Krashen’s theory. Each of the components relates to a different aspect of the language learning process. The five components are asfollows:
* The Acquisition Learning Hypothesis
* The Monitor Hypothesis
* The Natural Order Hypothesis
* The Input Hypothesis
* The Affective Filter Hypothesis
TheAcquisition-Learning Hypothesis
This hypothesis actually fuses two fundamental theories of how individuals learn languages. Krashen has concluded that there are two systems of language acquisition that areindependent but related: the acquired system and the learned system.
* The acquired system relates to the unconscious aspect of language acquisition. When people learn their first language by speakingthe language naturally in daily interaction with others who speak their native language, this acquired system is at work. In this system, speakers are less concerned with the structure of theirutterances than with the act of communicating meaning. Krashen privileges the acquired system over the learned system.
* The learned system relates to formal instruction where students engage in formalstudy to acquire knowledge about the target language. For example, studying the rules of syntax is part of the learned system.
The Monitor Hypothesis
The monitor hypothesis seeks to elucidate how theacquired system is affected by the learned system. When second language learners monitor their speech, they are applying their understanding of learned grammar to edit, plan, and initiate their...