Journal of Psycholinguistic Research, Vol. 28, No. 5, 1999 The Processing of Grammatical Gender and Number in Spanish Alberto Dominguez, 1,4 Fernando Cuetos, 2 and Juan Segui 3 The aim of the present study is to explore the representation and processing of inflectional morphol- ogy in Spanish. Experiment 1 compared the access time for words from the same base morpheme contrasted by the surface frequency of the masculine and feminine form, i.e., masculine-dominant items and feminine-dominant items. The results showed a surface frequency effect in both types of items. Experiment 2 compared the access time for masculine words having the same surface fre- quency but differing in their summed frequency (masculine plus feminine forms), the results showing no significant effect of this parameter. Finally, experiment 3 compared the access time for words from the same stem and contrasting by the surface frequencies for the singular and plural forms, i.e., singular-dominant and plural-dominant words. A clear frequency effect was observed for the singular- dominant words but not for plural-dominant ones. These results suggest that gender information is stored in the corresponding lexical entry and accessed from the full word form whereas the informa- tion about number is accessed from the stem corresponding to the singular form. INTRODUCTION A key question in psycholinguistics is how morphologically complex words are represented in the internal lexicon and how they are accessed during the word recognition process. Two different options are generally considered in the psycholinguistic literature related to the recognition of complex words. This research was supported by DGES research grant PB96-0545 to the second author and University of La Laguna research grant 24162-97 to the first author. We would like to thank Virginia Holmes, Ludovic Ferrand, Diego Alvarez, and two anonymous reviewers for their very helpful comments on a earlier version of the article. 1 University of La Laguna, Tenerife, Spain. 2 University of Oviedo, Asturias, Spain. 3 Laboratory of Experimental Psychology, CNRS and Rene1 Descartes University, Paris, France. 4 Address all correspondence to Alberto Dominguez, Departamento de Psicologia Cognitive, Universidad de La Laguna, Campus de Guajara, 38205 La Laguna, Tenerife, Spain. 485 0090-6905/99/0900-0485$16.00/0 © 1999 Plenum Publishing Corporation