As digital platforms increasingly mediate how learners engage with others in the social world, understanding the ideological and material conditions that shape these interactions has become a central concern in applied linguistics and language education. This talk introduces the constructs of platformization, digital socialization, and critical digital literacies (CDL), and demonstrates how they can be operationalized in empirical research to illuminate the unequal ways learners develop and enact digital literacy practices. Drawing on Poell et al.'s (2019) notion of platformization, the talk examines how the designs of digital platforms do not merely mediate interaction but actively constitute it, steering users toward specific behaviours and embedding particular ideologies. Digital socialization describes the dynamic process through which learners internalize dispositions toward digital technologies, negotiate platform affordances and constraints, and develop particular practices. Together with the concept of digital repertoires, the range of material, linguistic, semiotic, cultural, and social resources learners draw on, these constructs help examine how platformization shapes unequal opportunities for language learning. The talk then extends this framework to the domain of generative AI (GenAI), arguing that the same logics of platformization are deeply embedded in tools like ChatGPT, and that CDL, as the practices of interrogating and resisting how power operates in digitally mediated spaces, must be foregrounded as a pedagogical imperative in the age of AI. Drawing on my studies of learners' digital literacies surrounding social media and generative AI platforms (Darvin, 2025a; Darvin, 2025b), the talk illustrates how material conditions of access and platform design constitute learner dispositions and practices, and concludes with implications for educators seeking to develop critically informed, equitable approaches to digital literacies instruction.
