This document discusses different adverbials of time used in the English language including at, in, on, for, and since. It provides examples of how each preposition is used to indicate specific periods of time like clock times, seasons, years, months, parts of the day, days, dates, and durations. It also notes that no preposition is used with expressions like next week or yesterday. The document concludes with sentences for the reader to complete using the appropriate adverbial of time.

1. ADVERBIALS OF TIME at, in, on, for, since