Sirait, S. G. A., M. V. . Munthe, and N. M. P. . Hutabarat. “The Effect Of Substitution Drill To The Students’ Ability In Understanding Subject-Verb Agreement In Writing Descriptive Text”. Jurnal Ilmu Sosial Dan Humaniora , vol. 4, no. 1, Jan. 2026, pp. 86-98, doi:10.58540/isihumor.v4i1.1344.