Nicaraguan Sign Language (NSL) appeared only two decades ago among deaf children and adolescents attending new schools for special education in Managua, Nicaragua. The children's initial language environment provided severely degraded and incomplete linguistic input: they could not hear the Spanish spoken around them, and there was no previously developed sign language available. These learners responded by producing a gestural system with regularities that did not exist in their input, and in the process created a new, natural sign language. The language continues to develop and change as new cohorts of children enter school yearly and learn to sign among older peers. Consequently, there is a measurable discrepancy between the input to which each cohort of new arrivals is exposed and the language that they ultimately acquire. This discrepancy reveals a creative component of language learning.

By systematically comparing each cohort to the one that preceded it, we can detect new developments in areas central to the grammar of this emerging language. In this way, we can examine how grammatical systems develop; in particular, whether they are a product of certain tendencies of child learners. A series of comparisons reveals that the younger, more recent signers make use of emerging morphological devices in ways that the older signers who served as their language models do not. In this talk, we will view and discuss video examples of signing exhibiting spatial morphology. I will argue that these morphological devices have recently emerged to perform two functions: linking verbs with their arguments, and indicating location and orientation information. By examining these devices, we see that recent learners have reanalyzed and differentiated particular types of spatial movements, movements that are undifferentiated in the signing of the older children they learned from. Thus, by acquiring their language, these children are creating it.