Some conjunctions bring the subjunctive with them:

• para que — so that: Vou falar devagar para que todo mundo entenda. — I'll speak slowly so that everyone understands.
• embora — although: Embora seja caro, vale a pena. — Although it's expensive, it's worth it.

After para, when there's no new subject, simply use the infinitive: Estudo para passar na prova. — I study to pass the exam. And in conversation, mas often does the work of embora: É caro, mas vale a pena.

Others on the same list: antes que (before), a menos que (unless), caso (in case) and mesmo que (even if).