This study utilized a speech production test to examine how different components of the language faculty interact, focusing on the impact of morphosyntax and semantics on the intonation of Mandarin Chinese wh-indeterminates. The analysis of the hour-long speech production data from 33 speakers indicates that both morphosyntax and semantics play a crucial role in shaping the intonation of wh-indeterminates. We found that wh-indeterminates in complex clause structures effectively utilize all prosodic features to convey interrogative meaning. Moreover, when a morphosyntactic marker suggests a preference for a specific interpretation of wh-indeterminates, there is a reduced prosodic contrast (although still significantly different) between wh-interrogatives and wh-indefinites, underlying an interference effect of morphosyntactic cues in speech production.