Aspect splits can affect agreement, Case, and even preposition insertion. This paper discusses the functional ‘why’ and the theoretical ‘how’ of aspect splits. Aspect splits are an economical way to mark aspect by preserving or suppressing some independent element in one aspect. In formal terms, they are produced in the same way as coda conditions in phonology, with positional/contextual faithfulness.This approach captures the additive effects of cross-cutting splits. Aspect splits are analyzed here from Hindi, Nepali, Yucatec Maya, Chontal, and Palauan.

Argument coding splits such as differential (= split) object marking and split ergative marking have long been known to be universal tendencies, but the generalizations have not been formulated in their full generality before. In particular, ditransitive constructions have rarely been taken into account, and scenario splits have often been treated separately. Here I argue that all these patterns can be understood in terms of the usual association of role rank (highly ranked A and R, low-ranked P and T) and referential prominence (locuphoric person, animacy, definiteness, etc.). At the most general level, the role-reference association universal says that deviations from usual associations of role rank and referential prominence tend to be coded by longer grammatical forms. In other words, A and R tend to be referentially prominent in language use,while P and T are less prominent, and when less usual associations need to be expressed, languages often require special coding by means of additional flags (casemarkers and adpositions) or additional verbal voice coding (e.g., inverse or passive markers). I argue that role-reference associations are an instance of the even more general pattern of form-frequency correspondences, and that the resulting coding asymmetries can all be explained by frequency-based predictability and coding efficiency.