The document provides guidelines for common greetings and farewells in English based on the time of day. It suggests saying "good morning" between waking up and noon, "good afternoon" between noon and 5pm, and "good evening" between 5pm and 9pm as greetings. "Good night" should be said after 5pm as a farewell or after 9pm when going to bed. It then provides examples of short conversations using these greetings in different situations.