How does Prosody Distinguish Wh-statement from Wh-question? A Case Study of Standard Chinese

There are wh-sentences which express speech acts of interrogative or declarative with the same syntactic structure in standard Chinese, such as, "bǎobao chīdiănr shénme?"(What does the baby intend to eat?) and "bǎobao chīdiănr shénme."(The baby intends something to eat.) The interrogative pronoun "shénme" (what)has different semantic functions, such as specific reference in the interrogative sentence, and indefinite reference in the declarative sentence. The current paper focuses on the prosodic aspect of these kinds of wh-sentences based on some well-designed dialogues. Prosodic features are divided into local and global ones. Local features include prosodic cues of boundary syllables, the potential prominent word, the wh-words and the difference of prosody features between wh-words and the following boundary syllable. The global features include F0 spans, the regression of lines and the first order difference of F0 of the whole sentence. Fisher discrimination analysis shows that both global and local prosodic features contribute to discriminate the speech acts of those wh-sentences, but local features are more reliable than global features. The results indicate that features representing intonation components, such as sentence stress, boundary tones or even prosodic structures, must be considered in speech act discrimination besides syntax and context.