Sinaga B, Lumban Raja V, Ginting FYA. ERROR ANALYSIS ON THE USING BE OF SIMPLE PRESENT AND SIMPLE PAST TENSES AMONG THE SEVENTH GRADE STUDENTS OF SMP NEGERI 2 NAINGGOLAN. KAIROS [Internet]. 2020Jul.28 [cited 2024Jul.3];3(3):208-23. Available from: https://ejournal.ust.ac.id/index.php/KAIROS/article/view/841