Background: Children who do not produce single words by the expected age have been described as "late talkers" or as demonstrating "late language emergence" (LLE). Although their short-term growth in vocabulary is often strong, longer-term consequences of LLE remain in dispute. It has been argued that the majority of school-age…

This study investigates whether distinct neurodevelopmental disorders show distinct patterns of impairments in particular grammatical abilities and the relation of those grammatical patterns to general language delays and intellectual disabilities. We studied two disorders (autism and Williams syndrome [WS]) and two distinct properties (Principle…

At 3 years of age the spontaneous language of 17 typically developing children was compared to two groups of toddlers who were at risk for language delay for very different reasons. One at-risk group, late talkers, appeared normal in all respects except for their delayed language. These 20 children scored at or below the fifteenth percentile for…