Tone, intonation and their interaction in language contact: case studies of Nanning Mandarin, Nanning Cantonese, and Standard Mandarin

In tonal languages, fundamental frequency (f0) simultaneously encodes lexical tone and paralinguistic intonation. This dual use of f0 becomes more complex in language contact situations, particularly when the contacting varieties employ divergent prosodic strategies: Standard Mandarin extensively employs f0 modulation, including on-focus expansion and out-of-focus compression of f0 range (e.g., Y. Xu et al., 2012), whereas Cantonese relies less on f0 and lacks post-focus compression (e.g., W. L. Wu & Xu, 2010). How these distinct pitch systems interact within a variety arising from contact therefore remains difficult to predict.

This thesis investigates tone, intonation, and their interplay within Nanning Mandarin, a stabilised intermediate variant arising from contact between Nanning Cantonese (source) and Standard Mandarin (target). Through comparison with the source and target languages, it aims to provide the first systematic, acoustic-phonetic investigation of the pitch systems of Nanning Mandarin, an under-researched variety, and to examine the interaction between lexical tone and intonational focus as reflected in tone-specific focus effects.

Two production studies investigated the f0 realisation of lexical tone systems and intonational focus across the three Sinitic varieties, each recording over 60 native speakers. The tone study shows that Nanning Mandarin inherited the tone–contour mapping from Standard Mandarin, but exhibited greater similarities to Nanning Cantonese, taking similar-contoured Nanning Cantonese tones as main tonal templates. Regarding focus realisation, f0 patterns diverged across all three varieties. Although Nanning Mandarin resembled Nanning Cantonese more than Standard Mandarin in focus marking, unique focus realisation and tonal variation were observed, with very restricted focus-driven f0 modulation. These findings suggest that Nanning Mandarin, as a local variant of Standard Mandarin, may have developed distinct prosodic features, despite strong influence from Nanning Cantonese. The cross-linguistic divergence in tone-specific focus effects further suggests a complex tone–intonation interaction, requiring more fine-grained contour examination in continuous speech.