Effects of language dominance in Catalan-Spanish-English trilinguals' vowel-initial glottal marking: A Principal Components Analysis approach

Crosslinguistic influence (i.e., CLI, henceforth) in trilingual speakers is multidirectional and shaped by factors such as the amount of exposure to, and use of, each of the speaker’s languages. This study investigates whether relative dominance explains progressive and regressive CLI in trilingual speakers. To this purpose, we examine the production of word-external vocalic sequences (i.e., /V#V/) in L3 English speakers who are Catalan-Spanish bilinguals. Participants completed a reading task in English, Spanish, and Catalan that elicited vowel-to-vowel sequences along four levels of stress (i.e., stressed-stressed, unstressed-stressed, stressed-unstressed, unstressed-unstressed). Alongside the production task, they filled out a trilingual version of the Bilingual Language Profile (i.e., BLP, henceforth) (Birdsong et al. 2012). The resulting vocalic sequences were classified as instances of glottal marking (i.e., creaky phonation or complete glottal stop) or modal phonation. To examine the role of dominance, we ran a Principal Component Analysis on the questionnaire data, identifying four principal components that explained 57.9% of the variance. We compared L3 English vowel-to-vowel sequences with those of Spanish-English bilinguals who speak Catalan as an L3, as well as with L1 English monolinguals. We ran dominance-based logistic regressions for each language. In English, our results show that L3 English speakers differ from their L3 Catalan Spanish-English bilingual counterparts in unstressedstressed vowel sequences, but differ across all four stress levels when compared to L1 English monolinguals. Dominance-related principal components do not predict the rate of glottal marking in L3 English. In L1 Catalan and L1 Spanish, the use of glottalization is predicted by the average rate of glottal marking in the speakers’ L3 English productions, as well as by higher scores on the principal component associated with L3 English dominance. In Spanish, vowel-initial glottal marking is predicted by scores associated with low Spanish dominance. These findings highlight that dominance mediates CLI in trilingual speakers, which in turn reflects the dynamic nature of CLI in multilingual speakers.