This document provides instruction on the proper uses of the prepositions "to", "at", "in", and "into" in the English language. It explains that "to" indicates movement toward a place, person, or thing. "At" is used to point out specific times or locations. "In" is used for nonspecific times. "Into" indicates movement inside a place or container, or a change or transition. The document concludes with exercises applying the correct prepositions in different contexts.