English non-manner how-clauses as answers to deficient questions

English exhibits a variety of embedded how-clause that, while introduced by a canonically interrogative item, lacks an intuitive sense of interrogativity. This paper offers an analysis of the semantics of these clauses that is grounded interrogative semantics. On this view, how in these clauses introduces a degenerate, necessarily-singleton question set. Further, the paper observes that how here introduces a factive presupposition that cannot be reduced to the matrix predicate’s entailments. Accordingly, this paper supports a view on which factivity can arise from multiple sources. A diachronic-based account is also offered to explain the reccurence of how in non-manner embedded clauses cross-linguistically.