Subjunctive in Adverb Clauses / El subjuntivo en cláusulas adverbiales

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) main clause	conjunction	(indicative or subjunctive) adverbial clause
Siempre me siento feliz I always feel happy	cuando when	me llamas. you call me.
Hoy preparé la salsa Today I made the sauce	como the way	a ti te gusta. you like it.

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 most common conjunctions introducing adverb clauses:

Conjunctions of provision		Subjunctive?
a menos que	unless	always followed by the subjunctive
antes (de) que* con tal (de) que* en caso de que* para que* sin que*	before provided that in case so that, in order that without	always followed by the subjunctive*
Conjunctions of time
después (de) que* hasta que* tan pronto como /en cuanto mientras (que) siempre que cuando	after until as soon as while, as long as whenever, as long as when	use the subjunctive for anticipated circumstances (a future occurrence not yet met)
Conjunctions of condition
aunque a pesar de que como, según donde	although, even if in spite of, despite that as, in any way where, wherever	use the subjunctive for anticipated, hypothetical, or irrelevant circumstances (unknown at the moment)
* With these conjunctions, use the infinitive if there's only one subject (que not used): Voy a comer antes de salir. I'm eating before leaving (I eat, I leave)

No puedes ganar a menos que te apoyen. Se fue antes de que yo hablara con ella. Traje sombrero en caso de que haga sol. Trabaja para que su hijo pueda viajar. No puedes irte sin que hablemos primero. Cierre la puerta después de que salga. No quería esperar hasta que terminaras. Voy a regresar en cuanto caiga la noche. Cuando llegues, vas a sentirte mejor. Vamos a pescar aunque llueva mañana. Hazlo como quieras.

You can't win unless they support you. She went away before I could talk to her. I brought a hat in case it is sunny. She works so that her son can travel. You cannot leave without us talking first. Close the door after you leave. He didn't want to wait until you were done. I am going back as soon as the night falls. When you arrive, you'll feel better. We're going fishing even if it may rain tomorrow. Do it any way you want (as you please).

• Note that the conjunctions como, cuando and donde, unlike question words, do not have accents.

• sin que and a clause must be used in Spanish where English often uses a phrase such as "without us seeing him." Spanish must say: "sin que lo veamos / sin que lo viéramos".

• de la manera que, del modo que, are common equivalents of como, especially in writing:
Hazlo de la manera que te indiqué, o del modo que quieras.
Do it the way I showed you, or anyway you (may) want.

• para que has a variety of equivalent expressions that convey the idea of “so that”, “in order that”: a fin de que, con el objeto/propósito de que, con la intención de que.

• Use the indicative if time conjunctions do not refer to the future (actions in the past or in progress, known facts, habits):

Cuando llegaste, ¿te sentiste mejor? Esperó hasta que terminaste. Nos llama siempre que se siente solo. Está viendo la película mientras comemos.

When you arrived, did you feel better? (past) He waited until you were done. (past) He calls us whenever he feels lonely. (known fact) He is watching the movie while we eat. (in progress)

• The indicative follows aunque, como, según and donde to acknowledge a known place or fact:

Vamos a pescar aunque está lloviendo. Hazlo como te indiqué. Lo hice según indican las instrucciones. Vimos el campo donde luchó Bolívar.

We're going fishing even though it's raining. Do it the (specific) way I showed you. I did it as the directions (which I read) indicate. We saw the field where Bolívar fought.

Exercises and original page here.