The past perfect tense is formed using the formula below:

imperfect conjugation of haber + the past participle = past perfect

The imperfect conjugation of haber is shown below:

haber (full conjugation)

yo	había	(I)
tú	habías	(you)
él/ella/Ud.	había	(he/she/you)
nosotros (as)	habíamos	(we)
vosotros (as)	habíais	(you guys)
ellos/ellas/ Uds.	habían	(he/she/you)

The past participle is formed by adding the suffix -ado to -ar verbs and -ido to -er and -ir verbs.

Example: the past participle of hablar (to speak) is hablado. The table below shows the conjugation of hablar in the past perfect:

hablar (full conjugation)

había hablado	(I had spoken)
habías hablado	(you had spoken)
había hablado	(he/she had spoken)
habíamos hablado	(we had spoken)
habíais hablado	(you had spoken)
habían hablado	(they had spoken)

Yo no sabía si Juan había comido.
I didn't know if John had eaten.

Creía que ella se había acostado.
I thought that she had gone to bed.

¡Nunca habíamos estudiado tanto!
We had never studied so much!

No había dejado de llover.
It hadn't stopped raining.

Dijeron que se lo habian comprado.
They said they had bought it.