As the Dyirbal language of Australia nears extinction, its diminishing social function is accompanied by reduction within the linguistic system. If we place semi-speakers on a continuum according to the degree to which their language has been simplified, it is possible to trace changes in the grammar of the dying language. Focusing on morphological and syntactic ergativity demonstrates that decay in terminal Dyirbal involves systematic variation along the continuum. Reduction occurs on various levels, affecting syntactic operations and morphology. However, the data suggest that important formal and functional differences exist between dying Dyirbal and a typical pidgin.

Controversy exists over whether there is any connection between children's babbling and the development of the adult sound system. The classic proponent of the discontinuity school is Jakobson 1941/1968, who claimed that the pairing of sound and meaning drastically alters the child's sound system. Jakobson's arguments for discontinuity are here evaluated on the basis of data on the transition from babbling to speech in a single set of children recorded weekly in two contexts: mother-child interaction and solitary play. Using the data from the mother-child context, and comparing the sound system of babbling with that of the early words in terms of the distribution of consonants, vocalization length, and phonotactic structure, we find striking parallelism between babbling and words within each child, across time and within time period. The data constitute strong evidence for continuity.