Mohammad Yani Pehang, Darmanto Minggele, and Hanif Cahyo Adi Kistoro. “Improving Understanding And Learning Activities Of Simple Present Tense Declarative Sentences Through Whatsapp-Based Substitution Drills Techniques For Mtsn Students In Kupang City”. Linguanusa : Social Humanities, Education and Linguistic, vol. 2, no. 3, Nov. 2024, pp. 1-17, doi:10.63605/ln.v2i3.67.