The document discusses the past continuous tense in Spanish. It explains that the past continuous is formed by changing the verb "to be" from the present form (am-are-is) to the past form (was-were). The past continuous is used to describe what someone was doing when something else occurred, so there is often a past continuous action and a simple past action.

1. EL PASADO CONTINUO PAST CONTIUOUS Formación y usos