SECOND LANGUAGE ACQUISITION ON THE BASIS OF KRASHEN'S THEORY AFTER PUBERTY (I+1)

: This paper explores second language acquisition (SLA) after puberty through the lens of Stephen Krashen’s Input Hypothesis, particularly the concept of i+1. It discusses how language learners beyond the critical period face cognitive, affective, and environmental challenges, yet can still achieve high proficiency with comprehensible input slightly above their current level. The article reviews the Critical Period Hypothesis, empirical research on post-puberty learners, and pedagogical implications of applying i+1 in teaching. The study concludes that while naturalistic acquisition may be limited, structured exposure to meaningful input can foster continuous progress and communicative competence.