Spanish stative verb saber (to know) can change its lexical aspect to achievement ('begin to know') or to bounded state ('knowing for some time'), when it is in simple past tense (supo). This suggests that the type of situation does not depend only on the perfective operator. This paper, based on the analysis of 232 cases collected from the current Spanish language corpus of the Real Academia Espanola (CREA), shows that lexical, grammatical, and discursive meaning affect the determination of the type of situation of supo. The specific interpretation depends on the properties of the reference time in which the situation is located.