Subject + had + past participle+ complement.

• focuses in the RESULT of the action.

  Example: I had finished my homework before dinner.

  Key expression: before, afther, by the time, already and just.

When to Use the Past Perfect:

-To show that one past action happened before another past action.
- To explain the cause of something in the past.
-With before and after to show the order of events.
-In questions and with just/already to emphasize timing.

or is used to describe actions ONGOING before another past actions.

subject+had been + verb (-ing) + complement.

• Focuses on the DURATION of the action.

  Example: She had been studying for hours before the exam.

  Important: Pay attention to the order and duration of events.

  Key expression: For, since,before, when and until.

• He was tired because he had worked all night.

• She had eaten before we arrived.

• I had never met her before that day.

Past pefect progressive:

• He had not been sleeping well before he went to the doctor.

• She had been working at the company for five years before she died.

• I had been reading for two hours before my friend called.