Using antes de que/después de que/luego de que with indicative or subjunctive..

Question

1. I notice that in the headings of this subject, the "de" is placed in parentheses and that while most of the examples keep the "de", a couple don't, that is only "antes que" is used. Can you explain why this is so? Is there a grammatical reason or rule?

2. Is there a subtle, nuanced difference between "Despues de que" and "Luego de que", or are they completely interchangeable regarding meaning and use?

3. Is the tense of the subjunctive verb in the subordinate clause (i.e., presente de subjuntivo vs. pretérito imperfecto subjuntivo) determined by the indicative tense in the main clause?

Accepted Answer

Hola Gerald
1. The reason to admit both después de... and después de que... seems to be related to a cross over between después de... and después que... - you can read here the explanation that RAE gives to this. 
2. No, there is no subtle difference, only that "luego de que..." is more commonly used in Latin America (although you may also hear it in Spain sometimes)
3. If you have a future or an imperative in the main clause, the natural sequence is the present subjunctive in the time clause: 
Yo voy a ir /iré al instituto después de que hables con mi profesor.
Ve al instituto después de que yo hable con tu profesor.
If you use the present indicative in the main clause, you normally find an indicative again in the time clause:
Yo siempre voy al instituto después de que mi madre habla con mi profesor.
We keep the indicative here because we are talking here of an habitual action.
And if you use a past tense in the indicative in the main clause, you then normally find a past tense in the subjunctive, like the imperfect subjunctive:
Yo fui ayer al instituto después de que mi madre hablara con mi profesor. 
I hope it clarified it.
Saludos
Inma

Answer

Cuatro mil gracias.