Previous comprehension studies using Picture Matching Tasks (PMT) have shown that, by the age of four, Spanish-speaking children have acquired the semantics of "estar" being able to calculate the implicature that a property introduced with "estar" does not hold independent of time as well as displaying some ability to integrate discourse information about properties that change in the course of a story. This study extends that line of research to children under the age of four. Thirty-eight monolingual Spanish-speaking children were tested in two PMTs. The results show that at age three children differ from older children in their interpretation of the copulas suggesting that the distinction between "ser" and "estar" with adjectives emerges between the ages of three and four.