INTERLANGUAGE DEVELOPMENT IN ADULT EFL LEARNERS: A LINGUISTIC PERSPECTIVE

Interlanguage theory provides a central framework for understanding how second language learners construct and develop linguistic systems over time. This conceptual study examines interlanguage development in adult EFL learners from a linguistic perspective, emphasizing grammatical, pragmatic, and developmental dimensions of learner language. Drawing exclusively on selected theoretical and empirical studies in second language acquisition, the article synthesizes research on grammatical growth, pragmatic transfer, variability, and fossilization in adult interlanguage. The analysis highlights that adult learner language is systematic, rule-governed, and shaped by instructional context, social interaction, and cognitive maturity. Rather than viewing persistent non-target-like forms as deficiencies, the study interprets them as reflections of ongoing interlanguage restructuring. The findings suggest that meaningful linguistic development in adult EFL learners emerges through interaction, feedback, and form–meaning integration. The article concludes by discussing pedagogical implications for EFL instruction and emphasizing the importance of recognizing interlanguage as a dynamic linguistic system.