Similarly to tenseA grammatical category that is marked by verb inflection. To express when an event or action happens in time or when a state exists, we use tenses. changes, if the reported sentence is still true at the timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc. of reporting, no changes are made. If, however, the reported sentence is out of date, the following changes occur.