This paper aimed at examining Korean learners` grammar acquisition focusing on the tense use in complex-compound sentences. As such, we examined 13,748 words-size corpus of three intermediate mid to advanced low level learners` written texts over 22 months longitudinally. After annotation work with focused tagging set to mark the tense use clause and the error point, we analyzed quantitative results by SynKDP corpus analyzing program. Over 1,787 sentences including 1,450 conjunctive clauses and 1,178 embedded clauses, there were 29 conjunctive tense errors and 42 embedded tense errors. Frequency of errors implicated the importance of teaching adnominal clauses of embedded clause. Moreover, learner corpus also newly showed that there were strong discouragement factors in acquiring conjunctive clause tense use comparing to embedded clause tense use against conventional view. (Hoseo University, Kookmin University)