Without words, children can’t talk about people, places, things, actions, relations, or states, and they have no grammatical rules. Without words, there would be no sound structure, no word structure, and no syntax. The lexicon is central in language, and in language acquisition. Eve Clark argues for this centrality and for the general principles of conventionality and contrast at the core of language acquisition. She looks at the hypotheses children draw on about possible word meanings, and how they map their meanings on to forms. The book is unusual in dealing with data from a wide variety of languages, in its emphasis on the general principles children rely on as they analyse complex word forms, and in the broad perspective it takes on lexical acquisition.