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. Other common uses of these prepositions are also outlined. An exercise with fill-in-the-blank questions reinforces the different uses of these prepositions of place.