How do you use the pluperfect tense?

The pluperfect tense consists of the verb 'haber' in the imperfect tense and the past participle of the verb you 'had done'. The conjugation of haber in the imperfect tense is: habia, habias, habia, habiamos, habiais, habian So, to say, I had eaten, you would first conjugate the verb 'haber' in the imperfect tense in the first person singular: habia, and then form the past participle of the verb 'to eat': comer, which is comido. Thus: 'habia comido'