Cuando can be followed by the indicative or the subjunctive. It depends on what we want to express. To learn about the use of cuando for habitual or future actions see:
- Cuando + El Presente de Subjuntivo vs Cuando + El Presente de Indicativo
- Cuando + indicative for past events (subordinate time clauses)
In this lesson we will explain when to use cuando with El Imperfecto Subjuntivo, preceded by a main clause using El Condicional.
Here are some examples:
What is expressed after cuando is something the speaker sees as a possible thing to happen but with not much certainty, nearly as a conditional sentence with if.
Cuando + Presente de Subjuntivo or Imperfecto de Subjuntivo
When we use cuando with El Presente de Subjuntivo, the speaker sees the action as something with more probability to happen. The level of certainty is higher.
See the difference here:
Te ayudaré cuando te portes bien.
I will help you when you behave.
In the example above the speaker believes it is possible he will behave.
Te ayudaría cuando te portaras bien.
I would help you if [lit:when] you behaved well.
Here the speaker isn't very certain about him behaving. It is more hypothetical.
In reported speech
We frequently use this construction with cuando followed by El Imperfecto Subjuntivo is in reported speech (saying someone said that s/he would do something when something else happened). Have a look at the example:
The tense used after cuando is determined by the conditional used within the sentence expressing a reported speech:
Te prometo que te llamaré cuando aterrice el avión.
I promise I will call you when the plane lands.
It is important to remember that using
- Conditional in main clause + cuando + El Imperfecto Subjuntivo
has a similar meaning to a subordinate clause with "si" (if). Translating this use of cuando with "when" would be ungrammatical in English, but it is correct to use cuando with this meaning in Spanish.
Ella cubriría todos los gastos cuando él no pudiera pagar su parte.
She would cover all costs when if he couldn't pay his part.