This study explores the structure of learners’ argumentative texts in Korean written by heritage learners of Korean with a focus on students whose L1 is English or Chinese. In the light of argumentative writing, the texts are composed of more rigid rhetorical structures compared to other types of writing, and it is important to understand what the rhetorical text structures of a target language are for carrying out the writer’s argumentation successfully. While addressing this issue, we examined how learners’ L1s affect their argumentative writings in Korean by collecting data from advanced heritage Korean learners in America (L1: English) and learners studying abroad in Korea (L1: Chinese) at college-level. The participants took lectures related to their writing topics but any lecture on Korean argumentative writing was not given until they submitted all their writing assignments. Students were assigned three different argumentative topics and they were allowed to choose a topic to write. Data was collected from 15 participants of each heritage group and we focused on introduction and conclusion parts of their argumentative texts. In this study, we analyzed: (1) the structures of introduction and conclusions of learners’ texts using the adapted framework of Macro-Structure in argumentative writing from prior research; (2) how appropriate their structures are as a Korean argumentative writing using the framework of Super-Structure in argumentative writing; and (3) differences between the two heritage-learner groups (Korean-American and Korean-Chinese). Based on the analysis of the collected data, this study finds that most of heritage learners have difficulties in composing a successful argumentative writing structure in their texts apart from their mother tongues. They also show a tendency of executing their writing assignments relying on their oral proficiency with a lack of written forms and failures of writing successful argumentative texts despite their understanding the Macro-Structure of argumentative writing. In particular, the collected data illustrates that many heritage-learners have difficulties in writing Korean argumentative texts of the Super-Structure level. Finally, based on the findings, pedagogical implications and limitations are addressed for future research of teaching Korean argumentative writings.
