The document discusses the conjugations of the verb "to be" in the simple past tense in English. It states that "was" is used for the first person singular and third person singular subjects (I, he/she/it), while "were" is used for second person subjects (you), and plural subjects (we, they). It provides examples of affirmative, negative, and interrogative sentences using these conjugations of "to be" in the simple past tense.