Revisiting Case Contiguity: Case-functions, prepositions, and diachronic application

Caha’s (2009) ground-breaking thesis, The Nanosyntax of Case, unveiled a new approach to syncretism: (Case) Contiguity. Contiguity is a restriction on case syncretisms, corresponding to adjacency in an underlying hierarchy. When coupled with the Case Sequence, a posited universal hierarchy, this produces Universal Contiguity: an extreme predictive constraint on case syncretism. This paper delves into the narrative as it stands, re-examining and developing a range of topics involved in the implementation of (Universal) Contiguity in Nanosyntax. Integrating the Case Sequence with earlier functional granularity, and subsequent insights, a revised universal hierarchy is postulated: the elaborated Functional Sequence (eFS). Investigation begins with a case study of Icelandic inflectional and prepositional case expression, both of which are predicted to follow Contiguity. Results indicate that Contiguity and the eFS are upheld. Along the way, further granularity and diagnostic improvements are proposed, and an innovative model of inflectional decline: the deflexion frontier. This frontier progresses down the case hierarchy, gradually blocking suffixal inflection. Following the case study, Contiguity in prepositions is explored, and a novel metric for comparing the Nanosyntactic internal structures of case-functional Ps is presented. The next topic is syncretogenesis: the origin of surface-level syncretism patterns. It is shown that the underlying mechanism of syncretism, raising, can also account for surface-diverse phenomena such as non-autonomy and differential case marking: they simply differ in their operationalisations of the raising mechanism. Finally, the utility of Contiguity-based analysis is demonstrated across a range of historical and reconstructed conundrums. It is concluded that Contiguity remains tenable, and provides a versatile basis for analysis, fruitful in a range of settings (both synchronic and diachronic). Regarding universality, the eFS (although successful in the case study) will require considerably more testing and crosslinguistic evidence, particularly beyond Indo‑European, and definitional improvements must be made to ensure continued empirical integrity.