This document provides information on modal verbs and tenses used to talk about deduction, probability, intentions, and predictions in the past. It discusses the uses of may, might, will, must, can't, be going to, would, and the past perfect tense. Specifically, it notes that may and might express possibility, will and won't express certainty, and must and can't express deductions based on evidence. It also explains using the past form of be going to to talk about past intentions and would/wouldn't to talk about past predictions.