Pluperfect Subjunctive in Spanish Grammar
121spanish.com › pluperfect-subjunctiveThe subjunctive is used because we want to express doubt, subjectivity, uncertainty or possibility, rather than a definite fact. In order to form the pluperfect subjunctive in Spanish we need to conjugate the auxiliary verb HABER in the imperfect subjunctive form and then follow this verb with the past participle of the verb.