Taking a ‘discourse-centred online ethnography’ approach, this study aims to unpack the Hong Kong verbal practice of transborder conversations about social movement across the border with mainland China, driven by sojourn students during the Umbrella Movement from the theoretical viewpoint of speech codes. By conducting participant observation and in-depth interviews with 30 participants, two oppositional codes, cynicism and idealism, have been distinguished. Each code assumes diverse relations of the self and the state and diverse political expediency, which manifests as diverse interactional practices. The presence of these oppositional codes has imperiled the counter-hegemonic nature of transborder conversations.