Throwback Thursday: Grammatical Development in the Third Year of Life

How do young children learn the grammatical rules of their language, and what role does the language they hear play in this process? This Throwback Thursday, we revisit “Grammatical Development in the Third Year of Life: Individual Differences and Input Effects,” by Dr. Pamela Hadley and Dr. Matthew Rispoli, a research presentation exploring how children develop grammatical skills and how language input may influence this process.

The presentation focuses on the development of finiteness in English, including grammatical markers such as is, third-person singular -s, and past-tense -ed. These markers help children communicate information about tense and subject–verb agreement. Although children begin using these forms early in development, mastering them takes time, and children vary in how quickly they acquire them.

The research examines individual differences in children’s grammatical development, including how early growth relates to later grammatical accuracy. Findings highlight both shared developmental patterns and meaningful differences in the timing and rate of acquisition, demonstrating the value of examining children’s language development over time.

Another key focus is the role of language input, particularly the diversity of contexts in which children encounter grammatical forms. Exposure to grammatical markers across different words and sentence contexts may support children’s learning. The presentation also explores cross-morpheme facilitation, the possibility that learning one grammatical marker may support the acquisition of other related forms.

This research has important implications for understanding typical language development and identifying children who may be at risk for language difficulties. For speech-language pathologists, educators, and researchers, it underscores the importance of considering not only how often children hear language, but also the variety of linguistic contexts in which they encounter grammatical structures.

Watch the full presentation: Grammatical Development in the Third Year of Life: Individual Differences and Input Effects

Join us in revisiting this research and exploring how a better understanding of grammatical development and language input can inform future research and support children’s language learning.