If Clauses in Hypothetical Situations (cláusulas con “si” en situaciones hipotéticas)

First, if necessary, refresh your memory about the following points:

  1. El tiempo condicional
  2. El imperfecto del subjuntivo

Form

If Clause in the IMPERFECT SUBJUNCTIVE ... ... Main clause in the CONDITIONAL
Si practicara mucho ...
If I practiced a lot ...		 ... aprendería a hablar el español muy bien.
... I would learn to speak Spanish very well.
Si fuera un gato ...
If I were a cat ...		 ... dormiría todo el día.
... I would sleep all day.
Si lloviera esta tarde ...
If it were to rain this afternoon ...		 ... no iríamos al concierto.
... we would not go to the concert.

Note: The order of the two clauses can be reversed, but “si” always introduces the imperfect of the subjunctive:

Ejemplo(s):
No iríamos al concierto si lloviera esta tarde.

Uses of “Si” Clause in Hypothetical Situations

This structure is used to describe hypothetical or contrary-to-the-fact situations. If you take a look at the examples above, you will see that the speaker is expressing things that are not true and/or possible.

Ejemplo(s):
Si practicara más, aprendería a hablar el español muy bien.
If I practiced more, I would learn to speak Spanish very well.

In this context the speaker is admitting that she doesn’t practice her Spanish and doesn’t plan to. She is saying that IF she were to (would) practice more then she would learn Spanish very well, but that this is a hypothetical situation and will not actually happen.

Ejemplo(s):
Si fuera un gato, dormiría todo el día.
If I were a cat, I would sleep all day.

This is an clear example of a hypothetical or contrary-to-the-fact situation. Obviously, the speaker is not a cat! (But if he were, he would be a pretty lazy cat.)

Ejemplo(s):
Si lloviera esta tarde, no iríamos al concierto.
If it were to rain this afternoon, we would not go to the concert.

Here the speaker is expressing that she really doesn’t expect it to rain this afternoon. She uses the imperfect of the subjunctive (instead of the present tense) to communicate that she views this as a hypothetical situation and not what she expects to happen. However, if it were rain, then they would not go to the concert.

It is important to note that in English we use the past subjunctive in this situation, too. At least we used to… This form is not as common as it once was.

Ejemplo(s):
Si fuera tú, yo no haría eso.
If I were you, I wouldn’t do that.

In English, we can also say:

If I was you, I wouldn’t do that.

In Spanish you ALWAYS have to use the imperfect of the subjunctive to communicate hypothetical situations.