This paper presents an experiment on child interpretation of Spanish indefinites and bare singulars under negation. The findings show that Spanish-speaking children understand the scopeless property of bare singulars and that, contrary to what has been found in other languages, Spanish-speaking children pattern with adults by treating indefinite singulars ambiguously. These findings show that Spanish-speaking children do not treat bare singulars and indefinites the same and strongly suggest that the lexical ambiguity of the Spanish indefinite article (ambiguous between an indefinite and the number 'one') is playing a role in how Spanish children comprehend sentences containing indefinites.