Adverbial clauses precede the main clause, unlike the noun and relative clauses.
1) Conjunctions phrases that denote proviso, supposition, and purpose, are always followed by the subjunctive. These are the most common:
a fin de que (in order that, so that)
a menos (unless)
a no ser que (unless)
con tal (de) que (provided (that))
en case (de) que (in case that)
no sea (fuera) que (lest (so that...not), in case that)
para que (in order that, so that)
sin que (without)
ex: Lucas había sido indultado sin que su esposa lo supiese/supiera.
2) De modo que and de manera que (so that) take the subjunctive when they express purpose; when they result they take INDICATIVE.
Ex: El gerente platicó elocuentemente, de modo que condenara a los empleados
Ex: El gerente platicó elocuentement, de manera que condenó a los empleados. (INDICATIVO)
3) Aunque is the most common conjunction of concession which takes the subjunctive when it refers to an unaccomplished act or hypothesis, or when it indicates that the speaker does not believe the statement to be a fact. Otherwise, the indicative is used.
Ex: Aunque me lo juraras no lo creería.
Ex: Aunque me lo juraste no lo creí.
