The ethical and professional responsibility of any teacher is providing feedback in second language acquisition. Extroversion and introversion are the most important factors of personality traits which can have significant effects on second language acquisition. Thus, the current study tried to explore the roles of feedback types (self-correction and teacher-correction) and learners’ personality traits (extroversion and introversion) on learning grammatical knowledge. To this end, 58 homogenate students out of 80 students were selected based on the Quick Oxford Placement Test. Based on Eysenck Personality Questionnaire,39 students were chosen. They were divided into two equal experimental groups A & Brandomly. Self-correction was used in group A, and teacher-correction was applied in group B. After administering a pre-test, post-test, and delayed post-test, the results were calculated on a two-way ANOVA. According to the outcomes, self-correction and introversion had very significant effects on grammar learning. In addition, introverted students were better on recalling of learned knowledge.