Overview of HABER
Usually, students’ first introduction to a perfect, or compound tense, is when they are taught the present perfect. This is a good time to inform them that while English has two forms of the helping verb have (has and have) for the present perfect, Spanish, as always, has six forms for each verb in each tense. However, it is also good to encourage them with the fact that the present perfect in Spanish is used exactly as the present perfect in English. Give them a few examples of the present perfect to show how it is formed in English and how it is used.
The second thing that you need to teach them is how to form the past particle (also called the passive participle because it is used with ser to form the passive voice constructions). There are only a handful of irregular past participles (any verb built on any of these will be irregular as well, such as absolver):
As you introduce each perfect tense, be ready to show how to go from English to Spanish. Note that there are 12 forms in Spanish that are equivalent to have or has in English (between indicative and subjunctive):
he / hemos / haya / hayamos
has / habéis / hayas / hayáis + past participle.
ha / han / haya / hayan
Likewise, there 12 forms in Spanish that are equivalent to had in English (between indicative and subjunctive):
había / habíamos / hubiera / hubiéramos
habías / habíais / hubieras / hubiérais + past participle
había / habían / hubiera / hubieran
Many students don't understand the future perfect, so I tell them that by the time class is over, I will have explained it to them!
habré / habremos
habrás / habréis + past participle
habrá / habrán
Finally, the conditional perfect, all forms of which being equal to would have + a past participle in English:
habría / habríamos
habrías / habríais + past participle
habría / habrían
Most students are introduced to the pluperfect subjunctive quite late in the academic year, so it is the continuing Spanish students who re-encounter it in the fall. For them, a good review of all the perfect tenses, by way of a synoptic conjugation is in order. Tell them that the preterite anterior (hube, hubiste, hubo…) is not used much in speaking anymore, but it translates as had also. Almost all of its uses have been taken over by the pluperfect they may be familiar with (había…). But the preterite anterior is still important however, since the form of the imperfect subjunctive of haber (hubiera…) is essential for forming the pluperfect subjunctive of every other verb (hubiera … + past participle).