We are happy to report that Chen Qu successfully defended her PhD dissertation last Tuesday, May 21st. Her dissertation is titled “Representation and Acquisition of the Tonal System of Mandarin Chinese.” The abstract is below. Congratulations Chen!

This thesis examines the representation and acquisition of the Mandarin tonal system. The proposals raised in the thesis relate to three areas of phonological research: formal phonology, Mandarin phonology and the acquisition of phonology.

As far as formal phonology is concerned, the proposals are mainly three. First, concerning tone, the thesis supports the position of Yip (1980/1990) and Bao (1990/1999) that tones are internally structured. In particular, Bao’s (1999) model that contour and register are sister nodes is adopted. Departing from Bao (1999), however, it is suggested that a “register” node is not needed to express the internal structure of tones, due to the fact that there are only two registers across languages, H and L, and the two cannot be specified simultaneously. Second, the thesis supports the position that tone and stress can co-occur in tone languages, as the linguistic function of tone is to make lexical contrasts, while that of stress is rhythmic. Using evidence from stress in tone languages, it is argued that the uneven trochee should be recognized as one of the universal foot shapes, contrary to conventional views (e.g. Hayes 1995). Following discussion of the phonetic correlates of stress in different types of tone languages, it is shown that duration must serve as the principal phonetic correlate for stress in such languages because pitch is reserved for making lexical contrasts. Following from this, the uneven trochee, which is formed by a sequence of heavy/long and light/short syllables, arises as the optimal foot shape. Finally, the thesis identifies a relationship between stress and tone in contour tone languages as follows. There is a relation between rising tone and stress (prominence), and between level tone and lack of stress. A relation also holds between high register and stress, and between low register and lack of stress, as has previously been observed by Liberman (1975), Selkirk (1984, 1995), Goldsmith (1987) and de Lacy (1999, 2002, 2007) for register tone languages. The thesis proposes further that it is stress that determines the realization of tone, rather than the other way around: prosodic head (stressed) position makes tone high and rising; prosodic dependent (unstressed) position makes tone level.

Turning to Mandarin phonology more specifically, the proposals made in this thesis concern the formal representations of tones, prosodic structure and their interaction in tone sandhi processes. As far as the formal representations of tones are concerned, it is argued that Mandarin tones are underspecified: High register and rising contour are specified which, when embedded in a geometry where register (either H or L) and contour are sisters under the tonal node, results in the five-way tonal contrast of Mandarin, with T2 being the most marked/complex tone and T0 the least marked. Concerning the prosodic phonology of Mandarin, it is proposed that Mandarin is a weight-sensitive language and that a four-way weight distinction must be recognized: super-heavy (trimoraic), heavy (bimoraic), light (monomoraic) and weightless (moraless). Relatedly, it is argued that Mandarin strives to build uneven trochees, and that word-level stress falls on the leftmost heavy syllable in the domain of the phonological word. It is also proposed that phrasal stress in Mandarin respects End Rule Right. The overarching point made concerning Mandarin prosodic structure is that the language respects the prosodic hierarchy most commonly adopted for other languages (where moras are organized into syllables, syllables into feet, feet into phonological words, and phonological words into phonological phrases), in contrast to the position of many previous researchers working on the language (e.g. Yip 1980/1990, Duanmu 2007). As far as tone sandhi is concerned, this thesis provides a unified stress-based account for the three processes attested in the language: T2 sandhi, T3 sandhi and yi-bu-qi-ba sandhi. It is argued that T2 sandhi targets prosodic dependent position and changes the tone from more marked to less marked; T3 sandhi and yi-bu-qi-ba sandhi targets prosodic head position and changes the tone from less marked to more marked.

Turning to the acquisition of phonology, a hypothesis is formulated for children acquiring contour tone languages, which respects the Successive Division Algorithm (Dresher 2009) as well as Minimality and Monotonicity (Rice & Avery 1995, Rice 1996). This hypothesis leads to predictions for children’s tonal behavior at each stage in development, including the point at which tone sandhi should be acquired. It is predicted that children acquiring contour tone languages may vary at the onset of acquisition because Universal Grammar provides two possible launching points: “register” and “contour”. Subsequent stages in development are predicted to vary as well, if children acquire the tonal contrasts through repeated binary splits of the phonological space, as per the Successive Division Algorithm, and by adding one degree of complexity to representations at a time, following Minimality and Monotonicity.

The hypothesis for children’s acquisition of contour tone languages is tested against naturalistic longitudinal data collected from two children in northern China: GY and LL. The two children acquire the tonal system differently: GY focuses on “register” earlier than “contour”, whereas LL focuses on “contour” earlier than “register”. The children’s tonal behavior over time is also different, including the points at which they acquire tone sandhi processes. The cross-subject variation observed at the initial and subsequent stages of acquisition is shown to largely conform to the predictions.