The past perfect tense is used to describe actions that were completed before a specific time in the past. It is formed by using the past perfect tense of the auxiliary verb “to have” (e.g. “had”) and the past participle of the main verb (which is usually the same as the base form of the verb, such as “eat,” “drink,” “walk”).

Here are some examples of the past perfect tense:

1. “I had eaten breakfast before you called me at 8 o’clock this morning.” (action that was completed before a specific time in the past)
2. “The sun had risen in the east before I looked outside at 6 o’clock this morning.” (action that was completed before a specific time in the past)
3. “She had spoken Spanish fluently before I arrived at 7 o’clock this morning.” (action that was completed before a specific time in the past)

In the past perfect tense, the verb “to have” is conjugated to match the subject of the sentence, and the past participle is used to describe the action that was completed.

Conjugation Table

Here is a conjugation table for the past perfect tense, showing the verb forms for the subject pronouns “I,” “you,” “he/she/it,” “we,” and “they”:

Subject pronoun	eat	drink	walk
I	had eaten	had drunk	had walked
you	had eaten	had drunk	had walked
he/she/it	had eaten	had drunk	had walked
we	had eaten	had drunk	had walked
they	had eaten	had drunk	had walked

As you can see, the verb “to have” is conjugated to match the subject of the sentence, and the past participle is used to describe the action that was completed.