Past perfect tense
Usage
The past perfect tense is used to describe an action or event that happened before another past action or event. The past simple tense is used to describe the later action.
She had studied French before she moved to Paris.
The past perfect tense can also be used to describe an action or event that was unfinished at a specific point in the past.
He had been studying for three hours when his friends arrived.
The past perfect tense can be used to describe a cause-and-effect relationship between two past events. The earlier event is described using the past perfect tense, while the later event is described using the past simple tense.
She had lost her phone, so she couldn’t call her friend.
Form
The past perfect tense is formed using the auxiliary verb had followed by the past participle (-ed form) of the main verb.
I had finished my work before the meeting.
The theft had gone away before the police came.
Signal words
Signal words such as before, after, already, never, just, until, etc. are often used with the past perfect tense to give context and indicate the order of past events.
Negation and question forms
To form negative sentences in the past perfect tense, the word not is placed after the auxiliary verb had
I had not seen that movie before.
To form questions in the past perfect tense, the auxiliary verb had is moved before the subject
Had you finished your work before the meeting?