Constructivism   supports  learner-centered  pedagogy  more  than  the behaviorist and cognitive  theories.  The  behaviorist  and cognitive  theories  suggest  that  students  need to connect  with  their  learning  in  a personal  way  but constructivism  stresses comprehensive  learner-connectedness.

Dear Sadia nrasool,

In case you want to apply an ex post facto design, you should first try a correlation and then begin an ex post facto for discovering possible causality between the variables.Here, you have to specify if the knowledge of grammar helps , for example, learners' speaking skill in a meaningful way. Consequently, measure the relationship between the two sets of scores on grammar and speaking and then set up a pretest/post test control group design to see if grammar teaching affects speaking ability. wish you lots of luck with your research.

Best regards,

R. Biria

Chomsky's Competence Vs. Performance model provides a great interface between grammatical competence and actual language use. It paves way for considering the Universal Grammar Principles and Parameters, and how they relate to the language-specific cognitive device, known as the LAD.