SUMMARY
Learning adequate proficiency level in written English among learners of English as a second language is a very critical and challenging task for applied linguists, educators and governments.This study has investigated the relative impact of applications of provisions and principles of structural linguistics and communicative theory on performance in the written English of public Senior Secondary Schools Students in Kano State of Nigeria. The study has paid focused on two key pillars of any written discourse: content generation and expression skills. The stratified probability method of sampling has been used to select the six sample schools for the study and the systematic method of sampling has been used to select the twenty sample scripts for the study. The analytic scoring system has been used to score the sample scripts and descriptive statistics using percentages has been used to analyse the data. The results indicate that employing the principles and provisions of structural linguistics theory in written English among the subjects enables better content generation and expression skills than employing the provisions and principles of the communicative theory of language. The study recommends that both the teachers and textbook writers of written English in senior secondary schools should incorporate the provisions and principles of structural linguistic theory in the business of inculcating content generation and expression skills among the students.