The document provides an overview of modal verbs in the past tense in English. It discusses how modal verbs like "had to", "needed" and "could" have past forms, while others use "modal verb + have + past participle" like "must have". It provides examples of different past modal verbs and their meanings, including speculation, obligations, regrets and mistakes in the past. Practice examples are also included to help illustrate proper usage of past modal verbs.