Levels of Affixation in the Acquisition of English Morphology

The theory of level-ordering proposes that word formation processes are assigned to one of three levels within the lexicon. Level 1 processes are applied before Level 2, which are applied before Level 3. Such ordering constraints predict differences in acceptability between pairs such as teeth marks versus *claws marks, and Darwinianism versus *Darwinismian. An acquisition model is examined in which Level 1 forms are separately lexicalized, and Level 2 and 3 forms are more productive. Three untimed lexical-decision experiments were carried out with 5through 9-year-olds and found general support for a systematic relation between productivity and level assignment. However, a number of serious problems with the model are pointed out with regard to both linguisitic and empirical data. A revision of the model is posposed which appears to deal effectively with these problems. 6 1989 Academic Press. Inc.