Yardas, H. “The Student’s Errors on The Use Of Adjectives With The Suffix–Ly : Case Study SMA Negeri 13 Medan”. Cendikia : Media Jurnal Ilmiah Pendidikan, vol. 11, no. 2, Mar. 2021, pp. 82-96, doi:10.35335/cendikia.v11i2.1668.