A sentence consists of new and old information. The new information is known as 'focus'. Marking the focus in our speech prosodically (through rhythm, intonation and emphasis) helps our listener to process and understand our message. Liu investigated Bai-Mandarin early bilingual childred aged from six to thirteen and bilingual adults, based on which she could establish the developmental trajectory and ultimate attainment of prosodic focus-marking in Bai-Mandarin early bilinguals' Mandarin.
Route and rate of acquisition
Liu found both similarities and differences in the route and rate of acquisition of prosodic focus-marking between early bilingual children’s second language (L2) and monolingual children’s first language (L1). Regarding the developmental route, early bilinguals can use duration earlier than pitch for focus-marking purposes, similar to the monolinguals, but their use of prosody to distinguish narrow focus from non-focus is not earlier than distinguishing focus types, different from the monolinguals. Regarding the developmental rate, early bilinguals have not developed similar competence after five years of formal Mandarin education to that of the monolingual four- to five-year-olds.
Her results thus provide first evidence that early bilingual children’s L2 acquisition does not completely resemble monolingual children’s L1 acquisition in prosody, similar to findings on phonological acquisition but different from findings on lexical and syntactic acquisition. Furthermore, she has found that Bai-Mandarin early bilingual adults are highly proficient in using duration and pitch-related prosodic cues for encoding focus in Mandarin, but they are not fully Standard Mandarin-like.
Furthermore, her results show that L1 influence is evident in the bilinguals’ L2 development, which has been widely observed in bilingual language acquisition in different linguistic domains. Importantly, non-Standard L2 input might also influence the route and rate of acquisition in early bilinguals’ L2 development.