During our WOTJ critique group, we discussed the use of the subjunctive verb as to whether the word “wasn’t” or “weren’t” was more appropriate. There was general agreement that the sentence in question should be rewritten because it is bound to seem wrong to someone.
At any rate, Elisabeth Tuck did a little sleuthing on the subjunctive. Here are the results:
In English, verbal contexts called moods can be one of three types (as noted in http://www.ceafinney.com/subjunctive/guide.html):
• indicative – simple statement or question (Jill picks up the ball.)
• imperative – a command (Jill, pick up the ball!)
• subjunctive – a statement contrary to fact, a wish, a mandative (command) statement (I request that Jill pick up the ball.)
The site, http://www.ceafinney.com/subjunctive/guide.html, goes into far more detail about words that may indicate the need for subjunctive.
The following quotes are from http://www.grammargirl.com:
“Use subjunctive for times when you’re talking about something that isn’t true or you’re being wishful.”
“Although it’s not always the case, sentences that start with “if” are often also wishful or contrary to fact.”
When to use “was”, not the subjunctive:
“when supposing about something that might be true, use the verb “was.”
Ex: There was a storm in Mexico. If Richard was in Cabo, he could have missed the call.”
“The possibility that it happened is what makes this sentence need the indicative mood and not the subjunctive mood.” Grammar Girl.com