About what about: the semantics and syntax of irregular wh-questions in English

Although often used as diagnostic tools in discourse studies, irregular wh- questions in English, which take the form of what/how about ... ? and what/how if ... ?, have not received sufficient attention in terms of their semantic and syntactic prop-erties. This article investigates irregular wh-questions from semantic and syntactic perspectives. Semantically, there is a topic-comment relationship between the wh-word and the rest of the sentence. Syntactically, an irregular wh-question neither displays an explicit matrix subject-predicate structure nor involves a fronted auxiliary. This article pursues three objectives. First, a descriptive overview of irregular wh-questions is provided, which shows that the complement of about in irregular wh-questions can belong to various syntactic categories. Second, the topic-comment structure of irregular wh-questions is compared with that of the topic-comment structure in declarative sentences, which reveals some semantic properties of irregular wh-questions. Third, a formal account of irregular wh-questions is formulated in the framework of Dynamic Syntax, which captures the interaction of the semantic and syntactic properties of the components of an irregular wh-question. Additionally, the present dynamic account of irregular wh-questions is contrasted with an existing dynamic account of the hanging topic construction in English, which highlights some merits of the current account.