The difference between the Past Perfect Simple and Past Perfect Continuous:
Sometimes there is no apparent difference.
- Mary had lived in Paris for three years when she got married.
- Mary had been living in Paris for three years when she got married.
Normally the difference is:
- Past Perfect Simple for completed actions.
- Past Perfect Continuous when we are interested in the action over a period of time.
- By six o’clock I had painted the table and the chairs – They were now blue.
- My hands were blue because I had been painting the chairs and table.
Remember that certain verbs are considered to be Non-continuous verbs we would say:
- John had had three cars before he bought his Mercedes
- and NOT
John had been having three cars before he bought his Mercedes