Irrealis of the past tense indicates that everything
is actually too late and we sit afterwards and think
If we had done things differently
we would have been rich now. The English grammar
says that this kind of sentences are created with the
past perfect and the conditional perfect.
If the dog hadn't eaten
(past perfect) the lottery ticket we would
have won (conditional perfect) the 10 million
Euro. (but the dog has eaten the lottery ticket and
we did not win)
The Spanish Irrealis is formed with
the subjuntivo plusquamperfecto
in the si-sentence
and the condicional perfecto
in the second part of the sentence.
dado el dinero,
si me lo hubiera (hubiese) pedido.
I would have
given him the money,
if he had asked me.
construido la casa,
si hubieramos tenido dinero.
have built the house,
if we had had the money.*
ido a España,
si no se hubiera quebrado una pierna.
have gone to Spain,
if he hadn't broken his leg.
si hubiéramos sabido qué os hace falta.
have given you something,
if we had known what you need.
* in this example the second
sentence could also be
if we have had the money,
but actually it is only a question of phonetics. It just
sounds better. Grammatically the correct form is had