Past perfect continuous tense            When highlighting the length or continuity of an activity…

2.Reason behind a former event or circumstance:      To demonstrate how a current action led…

3.History of a former occurrence:        To give background information about a Past…

4.Recurring Action before another previous Action:    To characterize behaviors that were commonplace prior to…

5.Interrupted previous actions:             To characterize prior events that took place throughout time…

6.Stressing the persistent character of a previous action:   To draw attention to an action's continuous…