1. The document discusses past tense in English grammar. Past tense is used to describe activities or events that happened in the past. 2. For nominal sentences, past tense uses "was" or "were" with the verb "to be". For example, "I was a teacher" or "You were late". 3. For verbal sentences, past tense uses the past form of the verb. For example, "I wrote a letter" or "She cooked dinner". 4. The document provides examples of using past tense in both nominal and verbal sentences in positive, negative, and interrogative forms.