The document discusses the rules for changing direct speech into indirect speech in 3 sentences:
1) Pronouns, tenses, places, times and other contextual references need to be changed according to reporting verbs used in indirect speech.
2) Questions and actions like orders or requests also require grammatical changes such as using "if/whether" for yes/no questions and keeping the wh- word for wh- questions.
3) Modal verbs and verbs referring to present and future tenses may sometimes remain unchanged between direct and indirect speech depending on the context.