When we talk about something that happened in the past, we might want to refer to something that happened before that time. To do this we use the past perfect.
Look at these two sentences:
My friend left the bar at 10.00
I arrived at the bar at 10.30
Both actions happened in the past but if we put the two sentences together;
When I arrived at the bar my friend had already left.
‘arrived’ is a past action but ‘had left’ shows me that the action happened before.
Here are more examples of the past perfect. Notice that the past perfect shows the action happened before, in an earlier past.
I had been in Malta for three weeks before I met Natalia.
I received an e-mail from an old school mate yesterday. I hadn’t heard from him for twenty years.
Now look at these two sentences:
Peter had prepared dinner when we arrived.
Peter prepared dinner when we arrived.
In the first sentence the past perfect tells us that Peter prepared dinner before we arrived but in the second sentence first we arrived and then Peter prepared dinner.
Past perfect continuous
The past perfect can also be used in the continuous.
I had been working with the publishing company for ten years before I got promoted.
It is a common mistake to use the past perfect too much or to use it to refer to a distant past – ‘The Chinese had invented gunpowder.’ is wrong and should be ‘The Chinese invented gunpowder.’ The past perfect should refer to an earlier time from a point in the past.