This study has been conducted to investigate the possible effects of presenting the syntax rules to the participants following the order of the X-bar parameters' availability and triggering the target language parameter resetting by emphasizing on the input. This objective led to devising and applying a new approach for teaching English grammar based on the X-bar theory and to test the efficiency of this approach on improving English grammar proficiency and general language proficiency in EFL learners. The efficiency of this approach was assessed through qualitative analysis (following the participants' progress during the course based on the class observations, field notes and interviews). Significant positive improvement in the participants' general language proficiency and English grammar proficiency was observed at the end of the program. It can be concluded that presenting and practicing the grammatical rules of a second language based on the order of the availability of the X-bar theory parameters positively affects the learners' language proficiency.