A review of the literature on child language reveals little research on overgeneralization in the speech of the bilingual child. Questions arise regarding (1) the existence of interlingual overgeneralizations, and (2) the possibility that monolingual deviations and bilingual code switching might be forms of overgeneralization. Because a model for identifying overgeneralization in other languages or in bilinguals is lacking, a competence-based model and definition of overgeneralization are supplied in this study. Using this model and definition, 42 overgeneralizations are identified in the language samples of five Spanish-English bilinguals between the ages of two and five. Spanish was chosen for the study because its great variety of root and affix variants allows greater scope for the discussion of preference. No "interlanguage overgeneralizations" were found, possibly indicating that inflections become language specific earlier than entire lexemes. In both Spanish and English, affix markers are preferred over other types of internal markers. Frequency of use of roots and affixes by adults in the child's environment apparently determines the child's preferred roots and affixes. A suggestion is made that the is a distinct type and is a result of a different process. Actually, they are all an attempt at simplification and so are overgeneralizations. (Author/AMH)