grammaticality - Which is correct: "what if there was" or "what if there were"?

Is this correct grammar?

What if there was a site on…

Shouldn't it be "what if there were a site on…"?

Answer

Prescriptively, you're correct, this should be were since this is being expressed with the subjunctive mood. Descriptively, I think you'll find both in the wild. In informal speech, most people I know would prefer was in this case (and those that don't are sticklers for the subjunctive). I do think that you are much more likely to see were written though, especially in formal writing. Either form is correct, and the subjunctive forms are far from dead.

A more interesting question, I think, is whether or not the subjunctive mood is still being used and if the two forms have simply collapsed together. Is this a meaningful distinction? How could this be tested?