WIWIN KUSUMA DEWI. 2010. SKRIPSI. The Effect of English Grammar Mastery on Writing Ability of The Eighth Year Students of SMP Negeri 4 Jatibarang Kabupaten Brebes in Academic Year 2009/2010. Thesis. Strata 1 Program. The Faculty of Teacher Training and Education, Pancasakti University Tegal. Key word : The effect, English grammar, Writing ability. The purpose of this research is to know …