This study explores whether textual enhancement improves learners' acquisition of prefect tense structures in English. The perfect tense in English was taught explicitly in this study and then reinforced through input enhancement activity. The experiment involved 44 undergraduate students (experimental group 23, control group 21) taking practical English at a local four-year university in Korea. After explicit instruction, the two groups took a pretest, a reading comprehension activity, and then a post-test. After four weeks, the delayed test was conducted. In the experiment, the only difference between the two groups was whether the text was reinforced in the subsequent reading activity after the pretest. In online tests, participants were required to select the correct verb tense from multiple choice questions. The two groups had similar test scores, and there was no difference in the perfect tense acquisition between the two. However, when examining the differences within groups, the experimental group retained relatively high levels of perfect tense knowledge on the delayed posttest, whereas the control group did not. The results of the study demonstrated the synergistic effect of the textual enhancement technique when it is coupled with explicit grammar instruction. Furthermore, this study is important in that explicit grammar instruction is separated from input enforcement to allow the effects of it to be examined independently.