Conceptually speaking, the future and conditional perfect verb tenses in Spanish are similar — each tense expresses completed action in a future time. The similarities end there, however, because the future tense expresses action that’s almost sure to be completed in the future, whereas the conditional perfect carries a great deal of doubt concerning the outcome. The following sections provide additional guidelines to help you distinguish between these two compound tenses and choose the tense that best suits your needs.
Using the future perfect
The future perfect is packed with promise. Use it when the outcome is almost certain. This tense lets you
Express what will have happened by a given time in the future:
Nosotros habremos terminado para las dos. We will have finished by 2 p.m.
Ellos habrán llegado para este fin de semana. They will have arrived by this weekend.
Use para to introduce the time expressions in these sentences.
Express probability or conjecture (when a slight doubt exists) of a recent past action:
Ella lo habrá terminado. She has probably finished it.
Ellos habrán llegado. They must have (probably have) arrived.
Using the conditional perfect
Use the conditional perfect to express an action that would have happened but didn’t. Such sentences typically contain a dependent clause explaining why the action did not occur; this is your excuse clause — the one that gets you out of trouble.
When forming the dependent clause, keep the following two rules in mind:
When this dependent clause begins with but, the verb in that clause is in the indicative.
When the dependent clause begins with if, the verb in the clause is in the imperfect subjunctive.
Following are a couple of examples that show the conditional perfect at work in a real, live sentence, complete with a dependent clause:
Nosotros habríamos ido, pero teníamos que trabajar. We would have gone, but we had to work.
Él habría hablado con ella, pero no entendía la situación. He would have talked with her, but he didn’t understand the situation.
Note: Use the indicative after but in the dependent clause.
Ellos habrían ganado más dinero, si hubieran trabajado más horas. They would have earned more money if they had worked more hours.
Tú habrías salido más temprano, si ellos te hubieran llamado a tiempo. You would have left earlier if they had called you on time.
Note: Use the imperfect subjunctive after if in the dependent clause.
