The past perfect simple tense is used to go further back in time when we are already talking about the past. It can make it clear that something had already happened at the time we are talking about.

Past Perfect Simple Timeline

For example:

"I had already done the shopping by the time she came home."

"I was late for work, by the time I arrived the client had already left."

The past perfect simple can be used to show how often something happened in the past.

For example:

I'd visited the city many times before.

It can also be used to express unfulfilled wishes or dreams.

For example:

"If I had won the lottery I would have bought a new car." Note: If I had done something I would have done something else.