Abstract
Inferential vocabulary learning—deriving word meanings from context—plays a central role in vocabulary expansion, yet little is known about how writing systems shape learning outcomes and learners’ confidence in this process. This study investigated the effects of writing system on inferential vocabulary learning in learners whose first language uses the Latin alphabet. Forty-eight native Portuguese speakers learned pseudowords though incidental contextual inference. The pseudowords were presented in four scripts: Latin alphabetic, Cyrillic alphabetic, Arabic abjad, and Chinese logographic. Learning took place in either visual or auditory modality. After learning, we administered a recognition test with trial-by-trial confidence ratings. Performance was highest for Latin-based pseudowords, intermediate for Cyrillic, and lowest for Arabic and Chinese scripts, with a higher accuracy rate in the visual than auditory modality observed only for the Latin script. Difference in confidence on correct and wrong responses reflected metacognitive sensitivity, or learner’s faculty to detect those words that were less reliably learnt, and adapt confidence ratings accordingly. The results demonstrated robust metacognitive sensitivity across all conditions, with higher confidence for correct than incorrect responses. However, confidence on correct responses was selectively lower in the visual modality for abjad and logographic scripts, suggesting reduced processing fluency if the script is unfamiliar to the learner. Learning efficiency was positively correlated with confidence on correct responses. These findings show that script familiarity facilitates early lexical learning, while unfamiliar scripts increase processing demands and reduce learners’ confidence, without eliminating metacognitive sensitivity. The results highlight the importance of early orthographic support and metacognitive awareness in L2 vocabulary instruction. We discuss implications of these results for theories of lexical learning and for instructional practices for target languages with nonalphabetical writing systems.