Possible Duplicate:
“Was” or “were” in subjunctive clauses
“If I was” or “If I were”. Which is more common, and which is correct?
Why have the subjunctive and indicative converged in Modern English?
I've been reading Warrior's Apprentice by Lois McMaster Bujold and there is a strange phrase in chapter 2:
"Not much." She shrugged. "He just mentioned it. I wish—I don't know. I wish my mother were alive."
That "I wish my mother were alive" really confuses me. Why is "were" used instead of "was"?