High-proficiency second language (L2) learners challenge much theory and methodology in contemporary sociolinguistic and L2 acquisition research, which suggests the need for honest interdisciplinarity when working in the interstices of style, stylization, and advanced acquisition processes. When to consider fluent and highly competent speakers of a language to be language learners in ways relevant to SLA theory is a fraught and contentious issue. This study suggests that highly fluent multilinguals provide key data on notions of nativelikeness and near-nativelikeness that are of value for understanding processes of acquisition and use. It suggests that relative judgments of nativelikeness are interactionally accomplished (membership) categorizations made on the basis of specific linguistic features relative to particular linguistic markets. The data for the study are taken from a unique population--namely, young people from multilingual family backgrounds, born and raised in Sweden, all of whom ethnically self-identify as Assyrian-Syrian but whose repertoires are complexly multilingual. All participants are generally perceived to be native speakers of Swedish on a daily basis. Nevertheless, at certain moments, these young people are reclassified as near-native or nativelike. The study analyzes their narrative accounts of metalinguistic reflexivity from occasions and interactional moments when they are classified as nonstandard speakers and, therefore, near-natives or learners. The findings suggest the necessity of revisiting notions of nativelikeness and account for the phenomenon in terms of register, voice, and identity relative to different symbolic and linguistic markets.