Human Development. Eric Bravick played an invaluable role in helping to code

Children often invent new words to express meanings for which they have learned no words or cannot recall conventional words. They do not do so randomly, but appear to utilize their knowledge of word-formation devices. The present study investigated the development of spontaneous lexical innovations during the preschool years. Instances of lexical innovations were identified in transcripts of 210 naturalistic conversations between an American English-speaking boy (2;4 through 5;0) and his parents. The boy’s innovations generally support and extend Clark’s findings regarding categories of innovations and provide some support for her developmental predictions based on the principle of simplicity. Many usages seem to be based on common, productive word-formation devices in English, particularly compounding, whereas others appear to be based on novel rules and language play. Various influences on the development of lexical innovation are discussed. When children wish to communicate an idea, they often coin or invent a word to suit their purposes. They may say, for example, that a toy operates by means of ’batterycation’, that when they break crackers into their soup they are ’crackering ’ it, and that a person riding a bicycle is a ’bicycler’. They may create these words to fill lexical gaps when they do not know or have forgotten the appropriate word (Clar