Past perfect continuous tense
Example: My father had been working for this multinational company for 20 years.
subject + had been + verb + ing
1. We use past perfect continuous to show that an action started in the past and continued up until another action took place.
- They had been playing football when George broke his leg.
- We had been watching a movie when the light went out.
2. Past perfect continuous tense is used to explain why an action or feeling occurred.
- I was very tired. I had been revising for the exam for more than four hours.
- He put on weight because he had been overeating.
3. We use past perfect continuous to talk about the duration of an activity which continued up to a specified point in the past.
- I had been learning Chinese for 6 months before I moved to Beijing.
- My dad had been working for 30 years when he retired.
Check the uses of the past perfect simple here.