In line with the Global Englishes principle, translanguaging, the most recent extension of codeswitching, plays a crucial role in English language teaching since translanguaging is seen as an effective tool for communicating. This paper reports the findings of an observational study aimed at investigating the use of translanguaging to foster interactional competence (IC) development among Thai learners in one-on-one "English as a foreign language" (EFL) tutorials. Its objective is to explore extended learner turns and listenership, the defining characteristics of IC. Based on a zone of proximal development (ZPD) in the sociocultural theory (SCT) of Vygotsky (1978), translanguaging and IC interplay in the study. Self-Evaluation of Teacher Talk framework (Walsh, 2006 & 2011) was an instrument employed to develop the learners' IC. A total of individual 25 Thai learners were tracked over eight weeks and studied in 200 dyadic EFL tutorial sessions conducted in a translanguaging instructional context. The findings suggest that 76 percent of them improved in terms of producing greater extended learner turns, and 100 percent of them registered convergence as the most common function of listenership to display their understanding of the lesson and to project incipiency speakership. In addition, the Thai students interacted through translanguaging in two different manners: a dependent manner, for those with not fully improved English proficiency, and an independent manner, for well-developed English proficiency (García & Kano, 2014). Given the findings, translanguaging enhances the Thai learners' IC in dyadic EFL tutorial sessions.