Learning to Use the Past Perfect Continuous Tense

Past Perfect Continuous is a complex verb formation that is mostly used in written language.  It is used to indicate an earlier past to the main narrative. In this way, its function is primarily to give background information on a story.  The Past Perfect Continuous allows you to talk about continuous actions which happened in an earlier time-frame to the main narrative. 

For example, you could say, I had been studying for three hours when the fire alarm went off. As you can see from our diagram, the Reference Point (R) of this sentence is on the extended period of studying. This is giving background information to the main narrative, which is that the alarm went off.

Unlike Past Continuous, this tense cannot bring you up to the present moment, as the construction locates the action in the earlier past. You can see more about Past Perfect in the Past Perfect section. Unlike the Past Perfect, which focuses on completed actions in Earlier Past (Action 1), the Past Perfect Continuous describes an ongoing actions in the past. Our section on Combining Actions has more.