Unused Concepts
Is there any concepts that we learn when studying the language that is rarely used or not used at all? For example, I saw somewhere that the Preterite Perfect is not used very much, instead the Past Perfect is much more common.
2 Answers
The future subjunctive is essentially only used in archaic or very technical legal usages and does not really need to be learned.
The preterit perfect is very rarely used and can probably be skipped, but its just the preterit of haber plus the participle so its easy. Still Ive never used the tense, although I use hubo as the preterit of hay all the time.
I personally have only learned the se versions of imperfect subjunctive on a receptive basis- I have no instinct for forming them, even though the only difference is that you use se instead of ra at the end which is easy enough. It is used though so you need to recognize it.
I likewise have to look it up to use vosotros, although again I understand them on a receptive basis- Maybe some day I will have the opportunity to visit Spain, but it doesnt seem likely. Again it is necessary to recognize it.
I have no feel whatsoever for vos forms, I tried them a little once, but again Argentina does not seem to be on my horizon anytime soon.
Maybe other people will have other ideas.
Spurnish:
All good comments from Bosque.
In addition, I would add that every structured course in Spanish figures these things out for you. If something is archaic, little used or used only in a few literary or legal styles they will not include them in their program.
I think the best thing to do, if you're not enrolled in a class, is to find a structured course and stick with it from beginning to end. Then find another structured course and do the same.
After the first structured course, start doing some reading in Spanish about topics that you are very familiar with. You will understand a lot of it and really learn Spanish by seeing things in context. I like to read articles on Spanish Wiki about baseball, golf, cities, countries, etc.
I, for example, started with the SpanishDict video course, then I did Duolingo in both directions (English to Spanish and Spanish to English), then I did Mango, then I did Lengalia which covers many advanced topics and has a lot of audio and video content.
In the meantime I participate in various games here and have submitted little stories and exercises for review, always including both the Spanish and the English. It is important to play an active part in your learning, not just read grammar lessons and take quizzes. I also plan what to talk about each time I go to a Mexican restaurant. I study a little before hand to figure out what I want to practice and how to ask questions. I try to go at non-peak hours when the servers are less busy and will take the time to talk.