This document discusses prepositions of place in English grammar. It explains that the prepositions "at", "on", and "in" are used to indicate location. Specific examples are provided to illustrate the uses of each preposition. The key uses are: "at" for specific locations, "on" for surfaces or streets, and "in" for enclosed spaces or areas. Additional examples are given for less common uses. An exercise is included for readers to practice identifying the correct preposition for different phrases describing location.