This study seeks to address a gap in our understanding of how corrective feedback (CF) influences second language (L2) learning by examining the specific impacts of oral and written CF on acquiring the third person singular -s in the simple present tense. The study examines these effects on both explicit and implicit knowledge. The research was conducted in five intermediate adult English as a second language classrooms in Peru ( N = 101), using a pretest–posttest design with one control group ( n = 24) and four experimental groups: oral recast ( n = 21) oral metalinguistic CF ( n = 18) written direct CF ( n = 16) and written metalinguistic CF ( n = 22). The results revealed no significant difference between oral and written CF; however, differences were observed based on measurement types and CF subtypes used. This study’s findings carry theoretical and pedagogical implications, contributing valuable insights to both second language writing research and pedagogy.