Abstract
In Spanish, the plural form in plural dominant frequency pairs, like "diente/dientes" [tooth/teeth], occurs more frequently than the corresponding singular form. On the other hand, for the singular dominant frequency pairs such as "cometa/cometas" [kite/kites], the singular form is more common than the plural. The recognition of singular forms by adult readers is dependent on the dominance factor, while the identification of plural forms relies on the frequency of the stem. Given that age and reading experience may influence morphological processing of words, we investigate the representation of singulars and plurals in Spanish primary school children in Third Grade (8/9) and Sixth Grade (11/12) and adults through a lexical decision task. Though children's lexical decisions were twice as slow as adults, the pattern of morphological processing was consistent across ages: dominant plural forms resulted in decision times that were comparable to those of non-dominant singular forms, while recognition of singular-dominant forms was quicker than recognition of plural non-dominant forms. It appears that singulars are accessed and stored in the lexical memory as separate entities, while plurals depend on their morphological closer relatives, in this case, the singular forms.