This study investigates how L1-Korean L2-English learners perform with regard to articles in both explicit and implicit tasks. It also examines the role of L1-transfer from Korean demonstratives to English definites in L2 article production. 21 native English speakers and 27 adult intermediate L1-Korean L2-English learners were tested. The participants completed an elicited imitation task (EIT, implicit) and a forced-choice task (FCT, explicit). In the EIT, participants repeated sentences with and without articles, while stating whether the sentence matched the picture. In the FCT, participants chose the correct article for each item. The same sentences were used in both tasks. The results showed that in the FCT, learners were target-like in anaphoric contexts, supplying the, but very frequently overused a in non-anaphoric (bridging) contexts, suggesting that they equate definiteness with previous-mention. In the EIT, learners were less target-like than native speakers, yet the patterns of the two groups were similar. We consider possible explanations for the different results obtained in the two tasks.