Past Perfect Continuous
The past perfect continuous tense shows that an action was ongoing up until another point in the past.
Formation
Subject + had been + verb-ing
I had been waiting for an hour when the bus finally arrived. She was tired because she had been working all day.
When to Use
- Duration before something in the past: They had been talking for over an hour before he arrived.
- Cause of something in the past: The road was wet because it had been raining.
Common Mistakes
Don't confuse it with past continuous. Past continuous ('I was reading') doesn't emphasize the duration leading up to a specific event.