Past Perfect and Past Perfect Continuous Tense

1. PAST PERFECT & PAST
PERFECT CONTINUOUS

2. Past Perfect
It is used to talk about an action which took place before
the past.
For example;
The train had left when we reached at the station.
When we reached the station, the train had left.

4. Past Perfect Continuous
It is used to talk about an action which continued for
sometime before the past.
For example;
It had been raining for 2 days when we reached Lahore.
When we reached Lahore, it had been raining for 2 days.