Rationale and Precautioning Clauses: Insights from A’ingae

We describe and analyze the semantics of rationale and precautioning clauses (i.e. in order to- and lest-clauses) through a detailed case study of two operators in A’ingae (or Cofán, iso 639-3: con, an Amazonian isolate): the infinitive -ye ‘inf’ and the apprehensional -sa’ne ‘appr.’ We provide a new account of rationale semantics and the first formal account of precautioning semantics. We propose that in structures such as [$p$ [(in order) to$q$]] or [$p$ [$q$-ye]], the rationale operator (underlined) encodes modal semantics where the goal worlds of the actor responsible for $p$ achieve $q$. In structures such as [$p$ [lest$q$]] or [$p$ [$q$-sa’ne]], the precautioning operator encodes modal semantics where the actor’s goal worlds avoid a recoverable situation $r$ which entails $q$ ($r\Rightarrow q$). We observe and account for three apparent asymmetries within the domain of rationale and precautioning semantics, which we dub precautioning semantics asymmetry, rationale polarity asymmetry, and precautioning encoding asymmetry. We thus elucidate the relation between rationale and precautioning clauses and make substantial predictions with respect to the cross-linguistic inventories of rationale and precautioning operators.