Past Perfect

She had learnt Japanese before she moved to Japan.

Had he seen his uncle when he came back?

By 1970,he hadn't graduated from the niversity.

The past perfect expresses an activity that was
completed before another activity or time in the past.

Examples:

She had cleaned the house before her husband came
back.

By the time he was 42,he had taught for 20 years.

As soon as he had graduated from university,he got
employed in a company.

They were arrested because they had demonstrated
in the street.

She wishes she hadn't been divorced.

After her neighbour raped her,she
suicided.