A bit of grammar...

Past Perfect

Examples:

You had studied English before you moved to New York.
Had you studied English before you moved to New York?
You had not studied English before you moved to New York.

We use PAST PERFECT for completed action before something in the past the past perfect expresses the idea that something occurred before another action in the past. It can also show that something happened before a specific time in the past.

She only understood¹ the movie because she had read² the book.

1- first action, simple past
2- second action, past perfect
-> one action happened before another action, past of the past.
Examples:

She never saw a bear before she moved to Alaska. Not Correct
She had never seen a bear before she moved to Alaska. Correct


                 I hope that helps a little!!
                                                       By daddy...Fábio!