If you are talking to someone about a past event, and want to talk about an event prior to that, then the past perfect can be a good way to clarify causality and timing.
The form is:
S (I/you/we etc.)+ had + past participle
Here are two examples of how the past perfect can be used:
So as you can probably see, we tend to use the past perfect to talk about an earlier past.
Think you get the idea? Let's explore more of its uses:
1). As we said before, the past perfect is great at clearly separating two past events and making it obvious that one event or state occurred before the other.
It, therefore, makes it very clear that the two events are linked or distinct from one another.
Take this for example:
In the first sentence, it’s clear that she was sad because her dad had passed away. This is because after makes it clear which event happened first (her dad passed away then she was sad). In the second sentence, however, it’s not as clear that she was sad because her dad passed away. Unlike the first sentence where it's made explicit which event happened first, it’s not as obvious whether she's sad because her dad passed away, or whether she was sad before he passed - was she sad then her dad passed away?
Take this next example too:
Again in the first sentence, it’s clear the tourists left Beijing because they had seen The Great Wall and thus didn’t have anything else to do. In the second sentence though, it’s again not as clear which event caused which.
The past perfect again is used here to make it 100% clear which event preceded which, and therefore which event caused the other.
2). It can also be used to talk about dreams, hopes and wishes that were not realised:
She had hoped to be married by now, but she wasn’t and it made her feel sad; he had wished to cook spaghetti carbonara, but he couldn’t as he ran out of eggs
3). It’s also commonly seen with ‘after, first/second etc. and that’:
It was the first time that Bobby had seen a whale; it was the second time we had spoken to Ms. Carlin; after he had been to Japan, he went to The Philippines