A preliminary study on the acquisition of Mandarin neutral tone by young heritage children

The present study examined the pitch and duration of three types of Mandarin neutral tone (T0) – the possessive particle -de, the noun suffix -zi, and reduplicated words, in four tonal environments (following T1/T2/T3/T4) produced by two heritage language (HL) children longitudinally at 3;0 and 4;0 and two children cross-sectionally at 4;0, comparing them with two adult native speakers. Unlike the monolingual children in a previous study, our results indicated that the HL children have not developed a robust neutral tone category by 4;0. Acoustic measurements showed that HL children shared similar shapes of neutral tone pitch contour across types and tonal environments with the adult speakers when they were at 4;0, with a falling pitch contour following T1, T2, T4 and a rising pitch contour following T3. However, even though both HL children and the reference speakers reduced duration while producing neutral tone compared to the preceding tone, significant differences were found for their duration variations; while the reference speakers produced neutral tone after T1, T2, and T4 with a shorter duration than T3 across types, the patterns of HL children varied according to different types of the neutral tone. Individual difference also existed among the HL children.