The document outlines the basic structures for the simple past tense in Spanish, including: 1) The affirmative structure uses the subject followed by the verb. 2) The negative structure uses the subject, auxiliary "didn't" and the infinitive form of the verb. 3) Interrogative structures use the auxiliary "did" followed by the subject and infinitive verb. 4) Short affirmative and negative responses to questions in the simple past use "Yes, I/you/he did" and "No, I/you/he did not."