No, this post isn't about wishing to be a werewolf, weretiger, werebat, or any other form or supernatural shape-shifting were-animal. I know, you are heavily disappointed. Pay attention anyway.
I am talking about which form of "to be" to use in a hypothetical situation, regardless if the subject is singular or plural.
For example: If I were to make up an example sentence. (See what I did there?) The subject (I) is singular, so the verb (were) should also be singular, right? But wait, Jane, you used the plural, were, not the singular, was. Why?
Because this sentence is a hypothetical sentence, and that makes it a SUBJUNCTIVE MOOD or SUBJUNCTIVE CLAUSE. A Subjunctive mood statement is one that expresses various states of unreality, such as a wish, emotion, possibility, judgment, opinion, obligation, or action that has not yet occurred.
An excellent indicator of the subjunctive mood is the word IF. If I were at work, I would not be bored. If I were a millionaire, I wouldn't have to get up so early. If I were a rich girl, I'd have all the money in the world. The word IF clues us into the fact that it is not a real situation. IF will not always be there, but most of the time, it will be.
Just remember, IF and WERE almost always go together. Your editor will thank you for it!