Beyond mutual exclusion: evolutionary pathways of classifiers and number marking

Abstract Languages express number through varied strategies, including grammatical number, classifiers and numerals. The global distribution of these strategies varies widely. Two main explanations have been proposed for this variation: (1) plural marking and classifiers are mutually exclusive, and (2) languages with restricted numeral systems lack classifiers. The relative importance of these factors remains under debate. This study tests the co-evolution of number marking (singular, dual, trial, paucal, plural) and classifiers in a global sample as well as more specifically in the Austronesian and Sino-Tibetan language families. Using Pagel’s discrete model of character evolution, I analyze data on sortal classifiers and number marking from the Grambank Consortium, the World Atlas of Languages, and the World Atlas of Classifier Languages. Two pairs of phylogenies for each family are used for comparison of results and extensive language coverage. The results show a correlated evolution between plural marking and numeral classifiers, although transition patterns differ. Overall, a trend towards the presence of plural marking emerges, but areal factors impact trajectories in Sino-Tibetan languages, including tendencies for transitions to the presence of both plural marking and classifiers. No systematic evidence of co-evolution was found for singular, dual, trial, or paucal, and classifier. Classifiers and number marking generally follow diverse evolutionary paths: in some lineages, only one feature persists, while in others, both are absent or both occur together.