<![CDATA[Mandarin language acquisition frequently focuses solely on memorising standard grammar while ignoring the sociolinguistic environment, leaving it vulnerable to pragmatic communication hurdles in academic encounters. Based on this topic, the purpose of this study is to examine and synthesise the influence of socioeconomic stratification on second language (L2) learners' use of Mandarin language variation. The study uses a Systematic Literature Review (SLR) method guided by the PRISMA protocol, with a qualitative theme synthesis strategy. The formal object of the research is based on domain theory and the variational sociolinguistics method, while the material object focuses on Mandarin learners' linguistic behaviour within interactional dynamics in higher education. The findings show that academic hierarchy has a substantial impact on sociolect forms; vertical interactions require the usage of conventional formal varieties, whereas horizontal relations evoke more flexible language variants. Furthermore, code-switching and code-mixing activities serve as both instructional scaffolding and identity negotiation tools, with sociocultural variables and first language (L1) backgrounds driving their effectiveness. This study suggests that Mandarin language variety in university contexts is not a grammatical error, but rather a reflection of students' pragmatic intelligence in responding to social class dynamics. As a result, it is advised that educational institutions incorporate sociolinguistic competency into their Mandarin language development curriculum.]]>
