subjunctive mood

Question

I am very confused with the use of subjunctive mode in hypothetical clauses intorduce by si and the second followed by conditional verbs. I found out there their are different modes, present ,past, imperfect 1&2 , pluperfect 1&2. How do I know which is to use,?

Accepted Answer

Hola Annie
The different tenses in the subjunctive need to be seen in different lessons, in different contexts, as there isn't one simple and quick explanation for this. It also depends on which type of sentence you use, what conjunction etc. 
If you are in level B2 for example, these would be useful for you. You could add them to your notebook: 
Aunque + the present indicative vs the present subjunctive in Spanish
Aunque + the imperfect subjunctive in Spanish
Como/cuando/ donde / quien with indicative or subjunctive in Spanish
Mientras with past tenses in the indicative and subjunctive in Spanish (subordinate time/conditional clauses)
Ojalá with past tenses in the subjunctive in Spanish
Para que followed by the present subjunctive in Spanish (purpose subordinate clauses)
Para que followed by the imperfect subjunctive in Spanish (purpose subordinate clauses)
There are a lot more. Through the "Library" you can type the word "subjunctive" and you'll find a lot more lessons there. 
Un saludo cordial
Inma

Answer

Hi there Annie -My Grammar Reference-book distinguishes between: fulfilled or fulfillable conditions - and those which remain unfulfilled [and even 'impossible' ones]. It is this second category which uses the imperfect [or pluperfect] subjunctive. An important point to remember, incidentally, is that you should never use the present subjunctive after the "If" [i.e., after the "Si"].Good luck with your studies - David Mc