Published online by Cambridge University Press: 01 January 2026
In a number of signed languages, the distinction between nouns and verbs is evident in the morphophonology of the signs themselves. Here we use a novel elicitation paradigm to investigate the systematicity, emergence, and development of the noun-verb distinction (qua objects vs. actions) in an established sign language, American Sign Language (ASL), an emerging sign language, Nicaraguan Sign Language (NSL), and in the precursor to NSL, Nicaraguan homesigns. We show that a distinction between nouns and verbs is marked (by utterance position and movement size) and thus present in all groups—even homesigners, who have invented their systems without a conventional language model. However, there is also evidence of emerging crosslinguistic variation in whether a base hand is used to mark the noun-verb contrast. Finally, variation in how movement repetition and base hand are used across Nicaraguan groups offers insight into the pressures that influence the development of a linguistic system. Specifically, early signers of NSL use movement repetition and base hand in ways similar to homesigners but different from signers who entered the NSL community more recently, suggesting that intergenerational transmission to new learners (not just sharing a language with a community) plays a key role in the development of these devices. These results bear not only on the importance of the noun-verb distinction in human communication, but also on how this distinction emerges and develops in a new (sign) language.
We are grateful to the Deaf individuals in the United States and Nicaragua who shared their time and languages with us; without them, this work would not have been possible. This research was supported by NIH R01 DC00491 from the NIDCD and 1654154 from the NSF to Susan Goldin-Meadow, NSF BCS 0547554 to Diane Brentari and NSF BCS1227908 to Diane Brentari and Marie Coppola, an NSF Graduate Research Fellowship as well as a Newton International Fellowship from the Royal Society of the UK and the British Academy to Molly Flaherty, and by the Center for Gesture, Sign, and Language at the University of Chicago. We thank Emily Miiller, Carolyn Mylander, Mark Resnick, and Markie Theophile for their assistance with the project, as well as our many colleagues who have discussed this research with us. We are also grateful to audiences at Theoretical Issues in Sign Language Research and Formal and Experimental Approaches to Sign Language Linguistics, as well as to the editors of Language and two anonymous referees for their helpful feedback and discussion. Any remaining errors are our own.