CONDITIONAL SENTENCES - GRAMMAR AND EXERCISES

Conditional Sentences

Utilizamos las oraciones condicionales cuando queremos hablar de una posible situación y sus consecuencias.

Las oraciones condicionales tienen dos partes: la oración subordinada (la oración que expresa la condición y comienza con if) y la oración principal, que enuncia el resultado o consecuencia. En la oración If it rains, I will stay at home, la oración subordinada es If it rains, y la oración principal es I will stay at home.

Debemos usar una coma para separar la oración principal de la subordinada cuando escribimos primero la oración subordinada y luego la principal. En caso contrario, cuando la oración subordinada sigue a la principal, no se utiliza coma:

                                    I will stay at home if it rains.

Hay varios tipos de oraciones condicionales:

CONDICIONALES DE TIPO GENERAL (TIPO 0)

If + Present Simple      Present Simple

Utilizamos dos tiempos presentes para expresar leyes naturales, reacciones habituales o algo que normalmente es verdad:

                If you heat ice, it turns to water.

                If there is a shortage, the price of oil goes up.

Otras combinaciones de tiempos verbales:

       [   If + Present Perfect — Present Simple

                 If they have lost any money, they report it to me.

       [   If + Present Continuous — Present Simple

                If the baby is crying, it is probably hungry.

       [   If + Present Simple — Present Continuous

                If an advertisement does not tell the truth, the advertiser is committing

                          an offence.

Para situaciones pasadas utilizamos dos tiempos pasados:

If I finished my homework early, I played with my computer

En este tipo de oraciones condicionales podemos utilizar When o Whenever en vez de If :

               When you heat ice, it turns to water.

               Whenever there is a shortage, the price of oil goes up.

CONDICIONALES DEL TIPO I (PROBABLES)

                           If + Present Simple         WILL + V

Cuando queremos expresar situaciones que son posibles o probables, el verbo de la oración subordinada va en presente y el verbo de la oración principal en futuro:

                      If you hurry, we will catch the bus.

Otras combinaciones de tiempos verbales:

   Ø  If + Present Perfect — Will + V

                If you have finished, I’ll give you another book.

   Ø  If + Present Continuous — Will + V

                If you are staying for another night, I’ll give you a better room.

   Ø  If + Present Simple — Imperative

                If you are tired, go to bed.

   Ø  If + Present Perfect — Imperative

                If he has finished, ask him to leave.

   Ø  If + Present Simple — Modal + V

               If you are hungry, you can make yourself a sandwich.

CONDICIONALES DEL TIPO II (IMPROBABLES O HIPOTÉTICAS)

                          If + Past Simple   WOULD + V

Cuando hablamos de una situación improbable, el verbo de la oración subordinada va en pasado simple y el verbo de la oración principal en condicional:

              If I dropped this, it would explode.

El pasado simple en la oración subordinada no es un verdadero pasado, sino que en realidad es subjuntivo, lo que indica improbabilidad o irrealidad. Puesto que el verbo BE sí tiene un pasado de  subjuntivo, que es were para todas las personas, se puede utilizar If I/he were en vez de If I/he was.

Sin embargo, siempre decimos If I were you para dar consejo:

       If I was/were offered a ticket, I would take it.

       If I were you, I wouldn’t do it.

Otras combinaciones de tiempos verbales:

Se puede usar might o could en vez de would para expresar posibilidad, incertidumbre o permiso:

   Ø  If + Past Simple — Might + V

                 If you tried again, you might succeed.

   Ø  If + Past Simple — Could + V

                 If it stopped snowing, you could go out.

Should + V se puede utilizar para indicar que la acción en la oración subordinada es improbable.

If + Should + V — Present Simple

If this machine should fail to give satisfaction, we guarantee to refund the purchase money.

If + Should + V — Imperative

If anyone should ring up, say that I’ll be back at eight.

If + Should + V — Would + V

If the police should find out, we’d all be in the most terrible trouble.

En inglés formal, cuando hay un verbo auxiliar en la oración subordinada, por ejemplo were o should,es posible invertir el auxiliar y el sujeto y omitir la partícula if:    Should + V — Present

Should this machine fail to give satisfaction, we guarantee to refund the purchase money. = If thismachine should fail...

Should the police find out, we’d all be in the most terrible trouble. = If the police should find out...

        Were — Would + V

Were it true, she would be released. = If it were true, ...

     CONDICIONALES DEL TIPO III (CONDICIONALES IMPOSIBLES O IRREALES)

         If + HAD + Participio pasado       WOULD HAVE + Participio pasado

Cuando hablamos de una situación pasada que podría haber ocurrido pero que de hecho no ocurrió, el verbo de la oración subordinada va en pretérito pluscuamperfecto y el verbo de la oración principal en condicional perfecto:

             If I had known, I would have bought it.

Otras combinaciones de tiempos verbales:

Se puede utilizar might have o could have para expresar una posibilidad que no llegó a realizarse:

Ø  If + Had + Past participle might have + past participle

              If we had saved more money, we might have gone on holiday.

Ø  If + Had + Past participle – could have + past participle

              If we had saved more money, we could have gone on holiday.

En inglés formal o literario, es posible invertir el auxiliar had y el sujeto y omitir la partícula if:

Had + Past Participle — Would Have + Past Participle

Had I realized, I would have told you = If I had realized...

OTRAS FORMAS DE DECIR IF

                    Unless + verbo afirmativo = If + verbo negativo

Unless it stops raining, we won’t go out. = If it doesn’t stop raining, we won’t go out.

Unless quiere decir ‘excepto con la condición de que / a menos que / a no ser que’ y no se puede usar en oraciones en las que algo sería el resultado de que otra cosa no ocurriese:

                   She’d be pretty if she didn’t wear so much makeup

                  *She’d be pretty unless she wore so much makeup

                         But for = If it were not for / If it had not been for

But for the storm, we would have arrived earlier. = If it hadn’t been for the storm...

                  Provided / Providing (that) = If and only if

             You can camp in my field provided you promise to leave no mess.

                     As long as / So long as = If and only if

             You can go out tonight, as long as you come back by midnight.

                      On (the) condition that = If and only if

         She agreed to come on (the) condition that she could bring her pet canary.

                       Suppose / Supposing (that)? = What if?

         Suppose the plane is late? = What will happen if the plane is late?

         Suppose he went by train? = What would happen if he went by train?

         Supposing no one had been there? = What would have happened if no one   

                                                                        had been there?

OTRAS FORMAS DE EXPRESAR CONDICIONES

Se pueden expresar condiciones con imperativos (+ or / and) o participios pasados:

Finish your homework, or you won’t go out. = If you don’t finish your homework, you won’t go out.

Do that, and you’ll be in trouble. = If you do that, you’ll be in trouble.

Defeated, they would come back to Spain. = If they were defeated, they would come back to Spain.

CONDITIONAL EXERCISES

CONDITIONAL EXERCISES

PARAPHRASING

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