How Children Learn the Meanings of Words (HCLMW) defends the theory that words are learned through sophisticated and early-emerging cognitive abilities that have evolved for other purposes; there is no dedicated mental mechanism that is special to word learning. The commentators raise a number of challenges to this theory: Does it correctly characterize the nature and development of early abilities? Does it attribute too much to children, or too little? Does it only apply to nouns, or can it also explain the acquisition of words such as verbs and determiners? More general issues are discussed as well, including the role of the input, the relationship between words and concepts, and debates over nativism, adaptationism, and modularity.