How to form the Past Perfect
We form the 'past perfect' tense with:
- the past tense of the helping verb 'have' = had
- the perfect (completed) form of the main verb = past participle
In other words, had + main verb (past participle):
- I had already finished it.
Past perfect tense can tell us that:
1. Something occurred before another action in the past.
- Jim had already finished his lunch when Bob saw him. (= both actions [Jim finishing lunch and Bob seeing Jim] happened in the past, but lunch came first.)
2. Something happened before a specific time in the past.
- I had never been to Australia until last year.
- He had been sick until yesterday.