Special uses of the past perfect tense

The past perfect tense is used for an action already completed by the time of another past action or for an action already completed at some specific past time.

Example sentences: Everyone had spoken by the time I arrived. Joanne noticed that the bird had flown away without touching the seeds.

Writers sometimes use the simple past tense when they should use the past perfect.

Example sentence with editing. Original sentence: We built our cabin high on a pine knoll, forty feet above an abandoned quarry that was flooded in 1920 to create a lake. Revised sentence: We built our cabin high on a pine knoll, forty feet above an abandoned quarry that had been flooded in 1920 to create a lake. Explanation: The past-tense 'was' has been replaced by the past perfect 'had been.

The building of the cabin and the flooding of the quarry both occurred in the past, but the flooding was completed before the time of building.

Example sentence with editing. Original sentence: By the time dinner was served, the guest of honor left. Revised sentence: By the time dinner was served, the guest of honor had left. Explanation: The word 'had' has been added.

The past perfect tense is needed because the action of leaving was completed at a specific past time (by the time dinner was served).

Example sentence with editing. Original sentence: When we arrived in Paris, Pauline had met us at the train station. Revised sentence: When we arrived in Paris, Pauline met us at the train station. Explanation: The word 'had' has been deleted.

Both the arriving and the meeting ocurred at the same time, so the past tense is correct in both clauses.