Variability and consistency in late bilinguals’ morphology
An ERP production study
Speaking a late-learned second language (L2) is supposed to yield more variable and less consistent output than speaking one’s first language (L1), particularly with respect to reliably adhering to grammatical morphology. The current study investigates both internal processes involved in encoding morphologically complex words – by recording event-related brain potentials (ERPs) during participants’ silent productions – and the corresponding overt output. We specifically examined compounds with plural or singular modifiers in English. Thirty-one advanced L2 speakers of English (L1: German) were compared to a control group of 20 L1 English speakers from an earlier study. We found an enhanced (right-frontal) negativity during (silent) morphological encoding for compounds produced from regular plural forms relative to compounds formed from irregular plurals, replicating the ERP effect obtained for the L1 group. The L2 speakers’ overt productions, however, were significantly less consistent than those of the L1 speakers on the same task. We suggest that L2 speakers employ the same mechanisms for morphological encoding as L1 speakers, but with less reliance on grammatical constraints than L1 speakers.