Adverb clauses modify the verb in the main clauses. They say something about how, when, where or why that action occurs,
and are always introduced by a conjunction:
||(indicative or subjunctive)
|Siempre me siento feliz
I always feel happy
you call me.
The subjunctive is used in adverb clauses when the action described in the clause is anticipated or hypothetical (a reservation, a condition not yet met, a mere intention).
Here's a list of the conjunctions used in this exercise:
|a menos que||unless||always followed by the subjunctive|
|antes (de) que
so that, in order that
|always followed by the subjunctive
(but use infinitive if both clauses share the subject)
después (de) que
|whenever, as long as
|use subjunctive for anticipated events (future)