INVESTIGATION OF GRAMMATICAL ERROR IN STUDENT’S ENGLISH WRITING AT UIN RADEN INTAN LAMPUNG AS BASIS FOR LEARNING MATERIAL DEVELOPEMENT. lentera [Internet]. 2022 Mar. 7 [cited 2026 Apr. 24];14(1):11-22. Available from: https://jurnal.stkippgribl.ac.id/index.php/lentera/article/view/287