The role of prosody in the identification of illocutionary types. Polar questions vs. request for confirmation in the L-Act taxonomy

According to L-AcT, prosody is the interface between the affective/pragmatic programming of the utterance (illocutionary act) and its linguistic filling (locutionary act) and is necessary for speech act identification. The paper presents a case study on Polar questions (PQ) in the LABLITA corpus. PQs record strong prosodic variability in Tuscan, other Italian varieties, and American English. Corpus-based tag-sets distinguish PQ from “Request for confirmation (RC)”, when the speaker presupposes what he is asking and does not really seek information. It is hard to say whether a question is a PQ or RC since their difference relies on the speaker’s state of mind, and no prosodic correlation was found. Moreover, given that the origin of speech is affective and is not a function of the context, the latter does not strictly determine the performance of one illocutionary type instead of the other. The paper presents data showing that prosody provides a distinctive feature for PQ and RC: a mountain for PQ and a slight valley for RC. Both pragmatic conditions and prosodic forms have been induced from corpus observations and replicated in experimental settings.