Morphological Processing in Spanish: Inflection and Derivation in Second Language Learners

Abstract

This dissertation investigates how L1 Spanish speakers and L2 Spanish learners (L1 English) process morphologically complex words in Spanish, with particular focus on whether inflection and derivation are accessed and decomposed similarly under varying temporal conditions. This question addresses ongoing theoretical debates about whether inflected and derived forms engage shared or distinct mechanisms during visual word recognition and how these processes may differ between native and non-native speakers. Three visual lexical decision experiments were conducted to test these questions directly: an unmasked priming task designed to assess overt facilitation, a masked priming task targeting early automatic decomposition, and a delayed masked priming task intended to probe whether additional processing time supports morphological access under conditions that limit conscious awareness. Spanish was selected as an ideal test language due to its productive derivational system and systematic inflectional paradigms. The unmasked task provided clear evidence that L1 Spanish speakers benefit from both full-form repetition and morphological relatedness when prime–target relationships are fully visible, with comparable facilitation for inflectional and derivational pairs. In contrast, no reliable facilitation emerged among L2 learners in the unmasked task, with only numerical tendencies suggesting a possible advantage for repeated forms that did not reach statistical significance. This null pattern limits strong claims about morphological processing in the L2 group and is likely attributable to variability in proficiency or task engagement rather than systematic differences in representation. Neither the masked nor delayed masked tasks produced consistent morphological priming effects for the L2 group, highlighting the methodological challenges of detecting early decomposition effects in online testing environments that rely on precise stimulus timing and prime visibility. By contrast, the delayed masked task did elicit clear facilitation for native speakers, with significant reaction time advantages for both identity and derivational primes relative to unrelated controls, while inflectional primes showed no comparable benefit—an asymmetry that does not fully align with classic predictions of automatic inflectional decomposition in L1. This pattern suggests that when minimal additional processing time is provided, subtle morphological and lexical priming effects can be detected in Spanish, but the stronger derivational advantage points to processing dynamics that merit further investigation. Overall, these findings confirm that native speakers reliably engage both inflection and derivation when processing conditions allow for overt access, while inconclusive results for masked paradigms and L2 learners highlight the importance of methodological rigor and participant selection when probing the temporal dynamics of morphological processing in first and second languages.