The Effects of Explicit and Implicit Instruction on the Use of Discourse Markers in Japanese EFL Learners’ Speech

This study investigated the effects of explicit and implicit discourse marker instruction on English as a foreign language (EFL) learners' speech. Learner corpus studies revealed that learners used a limited variety of discourse markers in speech and illustrated the features of their use of discourse markers compared to that of native English speakers. However, studies are scarce on how the lexical items, which can help learners communicate effectively, should be provided in classroom settings. To compensate for these shortcomings, the present study, partially based on Miura and Shimada's (2014) experimental design, analysed Japanese undergraduate students' speech data collected with two different teaching methods (i.e., explicit and implicit instruction) during the seven weeks of these online English courses. In the first week, a pre-test which comprised two speech tasks was conducted with the two groups. Then, they were given explicit or implicit feedback about the usage of target discourse markers using video clips and emails. The results of the post-test in Week 5 revealed that, although the frequency of the marker for example was significantly higher after the instruction, there was no significant difference in the frequency of the other target markers in both groups. However, some students who were given the explicit feedback were able to use markers such as how about and well in the post-test. Additionally, some students increased their repertoire of discourse markers after the explicit feedback. In Week 7, a speaking test including tasks similar to the pre- and post-tests was administered as a substitute for the delayed test. Although some easily accessible markers such as and and because were used in speech, the repertoire was limited in both groups. Hence, the explicit instruction of discourse markers may have a limited effect on EFL learners' speech.