Past Perfect Continuous Tense is used to express the action that started in the past and continued in the past for some time. It is also called Past Perfect Progressive Tense.
Structure or format of Past perfect continuous tense:
Subject + had + been + Base form(+ing) + object + time reference
1. Girls had been singing a song since afternoon.
2. The kind woman had been helping your parents for five years.
3. My uncle had been leaving in Delhi for months
4. My son had been studying hard during exams.
5. Grandpa had not been eating medicine for two months.
6. He had been laughing out loud since a little age.
1. Joshua had been playing football for two hours.
2. She had been studying since morning for her next exam.
3. My manager had been drafting the plan for a meeting for two hours.
4. I had been watching my favorite movie.
5. They had been working on this project since last year.