Purpose: Composite measures of children's use of tense and agreement morphology differ in their emphasis on accuracy, diversity, or productivity, yet little is known about how these different measures change over time. An understanding of these differences is especially important for the study of children with specific language impairment, given…

Purpose: Our purpose was to test the competing sources of input (CSI) hypothesis by evaluating an intervention based on its principles. This hypothesis proposes that children's use of main verbs without tense is the result of their treating certain sentence types in the input (e.g., "Was 'she laughing'?") as models for declaratives…