While much research has been conducted on interaction in second language acquisition, the interplay of key interactional mechanisms—Negotiation of Meaning (NoM), Language-Related Episodes (LREs), and translanguaging—remains underexplored in the context of Chinese as a Second Language (CSL). With Mandarin gaining prominence globally, understanding how CSL learners use these strategies during peer interaction is crucial for enhancing classroom practice and informing language pedagogy. This study investigates the development and co-occurrence of NoM, LREs, and translanguaging in the peer talk of eleven CSL learners enrolled in three proficiency-based university classes (novice-low, novice-high, and intermediate-low). The study uses audio recordings of collaborative tasks—information-gap, decision-making, and cultural discussions—conducted in natural classroom settings. Peer interactions were transcribed and analyzed through both qualitative discourse analysis and quantitative comparison. The analysis focused on the frequency and types of interactional strategies, patterns of co-occurrence between NoM and LREs, and the functional and affective uses of translanguaging. Key measures included learners’ use of clarification requests, self-corrections, lexical or grammatical focus, and the integration of first-language resources into discourse. Findings reveal a developmental trajectory in which learners progress from relying heavily on lexical negotiation and basic translation to demonstrating greater metalinguistic reflection and emotional regulation through translanguaging. At the intermediate level, over 75% of NoM instances were immediately followed by LREs, showing how learners used moments of communicative uncertainty to collaboratively reflect on language form. Additionally, translanguaging evolved from a tool for bridging gaps to a resource for managing discourse and expressing stance. These changes suggest a growing capacity for autonomous, socially situated language use. In contrast to prior studies that rely on scripted or experimental tasks, this research is grounded in spontaneous peer interaction, capturing the authentic dynamics of bilingual strategy use in real-time learning. The findings emphasize the importance of recognizing the interconnectedness of interactional strategies and creating classroom environments that support exploratory, collaborative talk. Ultimately, this study highlights how learners’ strategic integration of NoM, LREs, and translanguaging contributes to both linguistic development and classroom participation, offering practical implications for CSL educators seeking to foster meaningful peer interaction.