Book excerpt: Although there has been a surge in our understanding of children's vocabulary growth, theories of word learning lack a primary focus on verbs and adjectives. Researchers throughout the world recognize how our understanding of language acquisition can be at best partial if we cannot comprehend how verbs are learned. This volume represents a proliferation of research on the frontier of early verb learning, enhancing our understanding of the building blocks of language and considering new ways to assess key aspects of language growth.