Grammatical features vary widely across languages and thisvariation has been studied in detail. The functions of gram-matical features, however, are not entirely clear and a numberof puzzles remain. For example, why do some languages haverich feature inventories but others have few if any grammaticalfeatures? Why do many languages have features that appearto encode semantic information (e.g. animacy) that is alreadyknown to the listener? We present a computational frameworkthat addresses questions like these by formalizing one way inwhich grammatical features aid communication. We use themodel to illustrate how morpho-syntactic feature inventorieshelp to solve the problem of communicating semantic struc-tures under cognitive pressures
