Toddlers vary widely in the rate at which they develop vocabulary. This variation predicts later language development and school success at the group level; however, we cannot determine which children with slower vocabulary development in the second year will continue to have difficulty. In this article, I argue that this is because we lack…

Children with delays in expressive language (late talkers) have heterogeneous developmental trajectories. Some are late bloomers who eventually "catch-up," but others have persisting delays or are later diagnosed with developmental language disorder (DLD). Early in development it is unclear which children will belong to which group. We…

Recent research demonstrated that although 24-month-old infants do well on the initial pairing of a novel word and novel object in fast-mapping tasks, they are unable to retain the mapping after a 5 min delay. The current study examines the role of familiarity with the objects and words on infants' ability to bridge between the initial fast…

Classic approaches to word learning emphasize referential ambiguity: In naming situations, a novel word could refer to many possible objects, properties, actions, and so forth. To solve this, researchers have posited constraints, and inference strategies, but assume that determining the referent of a novel word is isomorphic to learning. We…

Two experiments demonstrate that 14- to 18-month-old toddlers can adaptively change how they categorize a set of objects within a single session, and that this ability is related to vocabulary size. In both experiments, toddlers were presented with a sequential touching task with objects that could be categorized either according to some…

Four experiments explored the processes that bridge between referent selection and word learning. Twenty-four-month-old infants were presented with several novel names during a referent selection task that included both familiar and novel objects and tested for retention after a 5-min delay. The 5-min delay ensured that word learning was based on…

Recent research on early word learning suggests that children's behavior when-generalizing novel nouns integrates their prior vocabulary knowledge with the specifics of the task. This study examines how these factors interact on the moment-to-moment time scale of the training children receive and the sequence of stimuli they are shown. In 1…

Two experiments explore children's spontaneous labeling of novel objects as a method to study early lexical access. The experiments also provide new evidence on children's attention to object shape when labeling objects. In Experiment 1, the spontaneous productions of 21 23- to 28-month-olds (mean 26;28) shown a set of novel, unnamed objects were…