This document provides guidance on using the prepositions "at", "on", and "in" in different contexts. It explains that "at" is used to indicate a specific time or place, such as "at 8 o'clock" or "at the bus stop." "On" is used to refer to surfaces, days, dates, means of transportation, and locations like floors. "In" is used with months, years, seasons, parts of the day, short periods of time, and when referring to being inside a place. It also provides examples of common phrases that use these prepositions, such as "famous for", "afraid of", and "interested in."