On the synchrony, variation and diachrony of adverbial exceptive clauses in Polish

In this article, I examine the synchrony and diachrony of adverbial exceptive clauses in Polish headed by the complex complementizer 'chyba że' (unless). Synchronically, I argue that 'chyba-że'-clauses are syntactically nonintegrated adverbial clauses and that they cannot be analyzed as negated conditionals, although both clause types can give rise to an exceptive interpretation. Diachronically, I provide an analysis according to which 'chyba że' (unless) is treated as a complex C-head that is due to head adjunction of the discourse particle 'chyba' (presumably) and of the declarative complementizer 'że' (that). Essentially, there are three main factors that paved the way for the development of the exceptive complementizer in Polish: i) syntactic adjacency of the discourse particle 'chyba' (presumably) and of the declarative complementizer 'że' (that) establishing a subordination relation between the matrix clause and the embedded clause, ii) movement of the conditional clitic 'by' from MoodP to the CP domain, and iii) accommodation of negation of focus alternatives. As it will turn out, this process was completed in Middle Polish (1543-1765).