CLÁUSULAS ADVERBIALES

If the action in the main clause has already happened, or happens habitually, then the INDICATIVE IS USED in the adverbial clause.

Conjunciones que siempre requieren EL SUBJUNTIVO. Clausula ESCAPA

If there is not change of subject in the sentence, a subordinate clause IS NOT necessary. Instead, the prepositions can be used without que and followed by the infinitive.

If the action in the main clause has not yet occurred, then the SUBJUNCTIVE IS USED after conjunctions of time or concession.
* aunque + indicative = Although
* aunque + subjunctive = Even if