When to Use "de" in Certain Adverbial Clauses

Question

As we study adverbial clauses and when to use which with the subjunctive, we've noticed the appearance of the preposition "de" in parenthesis after such phrases as "con tal (de) que," "antes (de) que," después (de) que: and others.

Can anyone offer me a simple explanation as to when we will, in fact, use the "de" in these phrases and when we can do without it?

Thank you very much.

Answer 1

As far as I know antes needs the de when it's followed by a noun, pronoun or infinitive. When preferences are expressed you should only use 'antes que'. But apart from those examples I think that you can use either fairly interchangeably.

Answer 2

I might be wrong on this one, but I think that you might be able to use it when the subject of the second clause is a verb. For example, "We went for a walk after buying our new running shoes." I wouldn't take this as a fact until someone can back this up. I wouldn't have even answered had someone else answered before me.

Thank you, Vida de Scott. I hope to hear from more because it is now also vexing a student I asked from Spain. We know it when we hear it, but what is the rule. Perhaps it is time I check with the RAE. - scratch2486, Nov 14, 2013