The Conditional.

* The use of the conditional in Spanish is similar to the use of the construction would + verb in English when hypothesizing about a situation that does not form part of the speaker’s reality.

Yo saldría temprano para el concierto.                        I would leave early for the concert.

* Spanish also uses the conditional to express probability in the past.

Estaba tomando café. Serían las diez                        I was having coffee. It was probably ten

de la mañana.                                                           in the morning.

The Imperfect Subjunctive.

The past subjunctive is also called the imperfect subjunctive. All regular and irregular past subjunctive verb forms are based on the ustedes, ellos/as form of the preterit. The following chart will help you see how the past subjunctive is formed. Note the written accent on nosotros forms.

                                    HABLAR         COMER          VIVIR              ESTAR           

                                    (hablaron)         (comieron)        (vivieron)          (estuvieron)

yo                                hablara             comiera            viviera                estuviera

tú                                 hablaras            comieras           vivieras             estuvieras

él, ella, usted                 hablara             comiera            viviera              estuviera

nosotros/as                   habláramos       comiéramos      viviéramos        estuviéramos

vosotros/as                   hablarais           comierais          vivierais            estuvierais

ellos, ellas, ustedes        hablaran           comieran          vivieran             estuvieran

* The present subjunctive is oriented to the present or future while the past subjunctive focuses on the past. In general, the same rules that determine the use of the present subjunctive also apply to the past subjunctive.

            HOY→ PRESENT SUBJUNCTIVE
             Los astronautas quieren que los trajes espaciales sean más liviános.
            The astronauts want that the space suits be lighter.

            Van a cambiar los trajes espaciales para que sean más liviános.           
            They are going to change the space suits so they’ll be lighter.

            AYER→ PAST SUBJUNCTIVE
            Los astronautas querían que los trajes espaciales fueran más liviános.
            The astronauts wanted that the space suits be lighter.

            Cambiaron los trajes espaciales para que fueran más liviános.
            They changed the space suits so they would be lighter.

* Use the past subjunctive after expressions como si (as if, as though). The verb in the main clause may be in the present or in the past.

            Gastan dinero en aparatos electrónicos como si fueran ricos.
            They spend money in electronic gadgets as though they where rich.

             Hablaba con el científico como si entendiera el problema.
            He talked with the scientist as if he understood the problem.

IF-CLASES.

1. Use the present or future in the main clause and present indicative in the if-clause to express what happens or will happen if certain conditions are met.

            Puedes obtener información sobre el Amazonas si la buscas en el Internet.
            You can get information on the Amazon if you look for it in the Internet.

             Los bosques desapareceran si continuamos cortando árboles.
           Forests will disappear if we continue cutting trees down.

Si cuidamos nuestros recursos naturales, las generaciones futuras tendrán una vida mejor.
If we take care of our natural resources, future generations Hill have a better life.
 

2. Use the imperfect subjunctive in the if-clauses to express a condition that is unlikely or contrary-to-fact. Use the conditional in the main clause.

        Si le dieran más dinero al aeropuerto, el tráfico aéreo podría mejorar.
        If the airport were to get more money, air traffic could improve.

         Si usáramos la energía solar en las casas, ahorraríamos mucho petróleo.
        If we used solar energy in our homes, we would save a lot of oil.