theories of second lang acquisition

https://en.wikipedia.org/wiki/Theories_of_second-language_acquisition

the above  link deals with various theories and hypothesis of L2 language acquisition.

http://www.sk.com.br/sk-krash-english.html

 the above link is about krashen’s theory of acquisition :

*meaningful interaction in the targeted language ; natural comm..

*comprehensible input; not forcing and correcting production.

His theories are :

• the Acquisition-Learning hypothesis;
• the Monitor hypothesis;
• the Natural Order hypothesis;
• the Input hypothesis;
• and the Affective Filter hypothesis.