The past perfect is a verb tense which is used to show that an action took place once or many times before another point in the past.
Past Perfect (englishpage.com)
Past perfect (britishcouncil.org)
// They'd finished the project by March.
// Had you finished work when I called?
// He couldn't make a sandwich because he'd forgotten to buy bread.
// The hotel was full, so I was glad that we'd booked in advance.
// My new job wasn't exactly what I’d expected.
// She'd published her first poem by the time she was eight.
// We'd finished all the water before we were halfway up the mountain.
// Had the parcel arrived when you called yesterday?
// When the police arrived, the thief had escaped.
// The thief had escaped when the police arrived.
They left before I'd spoken to them.
Sadly, the author died before he'd finished the series.
I called his office but he'd already left.
It still hadn't rained at the beginning of May.
I went to visit her when she'd just moved to Berlin.
It was the most beautiful photo I'd ever seen.
Had you ever visited London when you moved there?
I'd never met anyone from California before I met Jim.
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Statement: You had studied English before you moved to New York.
Question: Had you studied English before you moved to New York?
Negative: You had not studied English before you moved to New York.
USE 1 Completed Action Before Something in the Past
- I had never seen such a beautiful beach before I went to Kauai.
- I did not have any money because I had lost my wallet.
- Tony knew Istanbul so well because he had visited the city several times.
- Had Susan ever studied Thai before she moved to Thailand?
- She only understood the movie because she had read the book.
- Kristine had never been to an opera before last night.
- We were not able to get a hotel room because we had not booked in advance.
- A: Had you ever visited the U.S. before your trip in 2006?
B: Yes, I had been to the U.S. once before.
USE 2 Duration Before Something in the Past (Non-Continuous Verbs)
// We had had that car for ten years before it broke down.
// By the time Alex finished his studies, he had been in London for over eight years.
// They felt bad about selling the house because they had owned it for more than forty years.