Brazilian Portuguese 'in-situ wh'-interrogatives between rhetoric and change

Previous studies of the historical development of partial interrogatives have postulated a change from contexts in which the proposition of the interrogative has been explicitly mentioned in the previous discourse, to contexts in which the proposition is discourse-new. The present paper explores whether the historical increase in the usage frequency of Brazilian Portuguese 'in-situ wh'-interrogatives represents the same process. Using data from a large corpus of BP theater texts dated between the 19th and 21st century, several discourse functions of InSituWh are identified, the most frequent of which are cataphorical questions, which serve to either open up a question unrelated to the current question under discussion, or raise further questions about the current question under discussion, and rhetorical questions, which question the validity or relevance of a previously mentioned proposition. Rhetorical questions typically do not trigger a response by the interlocutor and are used with psychological verbs and morphologically simple interrogative pronouns. A statistical analysis of the diachronic distribution of InSituWh in the data reveals an increase in the usage frequency of InSituWh especially in contexts in which the proposition is discourse-new. However, the results also indicate that this increase is not due to a grammatical change of InSituWh but rather reflects a consolidation of the rhetorical question function of InSituWh within the genre of theater plays