Sensitivity to derivational morphology as cues to lexical stress among English as second language learners

Derivational suffixes are known to play a crucial role in assigning stress to multi-syllabic words among native English speakers. However, it is unclear whether second language (L2) learners of English can effectively use derivational suffixes as stress cues in written words. To address this gap, we studied if native Chinese-speaking adults learning English as an L2 can use derivational cues to correctly assign lexical stress, and whether the frequency of these suffixes and their L2 language proficiency moderate this sensitivity. Utilizing a written stress assignment and a stress production task, participants saw a series of written stems and their derived forms and were asked to either choose a syllable to assign the stress (Experiment 1) or read it aloud (Experiment 2). Results showed that L2 learners are sensitive to derivational cues to lexical stress in English. Moreover, the strength of this sensitivity is dependent upon the suffix class, frequency, and L2 language proficiency. Specifically, in both experiments, participants made more correct stress shifts in derived forms with high compared to low nonneutral suffix frequency; however, it did not differ between high and low neutral suffix frequency. In addition, as participants’ English proficiency increased, their correct stress shifts increased significantly greater in those derived nonwords with nonneutral than neutral suffixes in the stress assignment task. These findings make a significant contribution to the limited literature on L2 learners' sensitivity to morpho-orthographic cues to lexical stress and support the proposed statistical learning mechanism, that is, L2 learners can implicitly learn statistical regularities from linguistic materials.