Interactive roles of L1 properties and L2 textbook input for constructing L2 knowledge

Abstract This study investigates how morphosyntactic features of learners’ L1 (Czech; English) and characteristics of L2-textbook input jointly contribute to L2-Korean learners’ comprehension of Korean subject–predicate honorific agreement, focusing on the two mismatch conditions on the honorific status between a subject and a predicate. Textbook analysis revealed over-emphasis on the honorific suffix (and honorification in general) and unsystematic approaches to raising awareness of this knowledge. Acceptability judgement with reaction time measurement revealed learners’ global leniency in the grammatically incorrect condition and by-L1 asymmetries regarding acceptability ratings and processing cost for the infelicitous (but acceptable in actual language use) condition. Implications of this study’s findings are discussed with respect to the interplay between L1 properties and L2 textbook input in constructing noisy representations of L2 knowledge.