I wish I WAS...or WERE? Using the Subjunctive in English

In short, the answer is I wish I WERE, but most people say was these days, which is grammatically incorrect, and serves as yet another example of English losing its grammatical nuances that make it an expressive, complex and interesting language.  Another example of the weakening and watering down of the English language is evident in the quickly disappearing use of whom in speech. 

Grammatically speaking, were is correct because it defines the subjunctive mood, a tense once used in Old English that is still actually used today although unknown and not even taught to most English speakers. The concept of the subjunctive has remained the same (expressing a wish, suggestion, requirement or demand), but the grammar does not require an entirely different conjugation, as it did in Old English. Most likely English speakers have more experience with this grammatical tense through learning Spanish, Portuguese, French or other Romance, Slavic, Germanic or Celtic languages.

The Subjunctive in English:

Note that the subjunctive mood in the verb to be only changes in the first person and third person singular as seen in bold below:

Wishes:

I wish I were...
You wish you were...
She wishes she were...
We wish we were...
They wish they were...

If I were a painter...
If you were a painter...
If she were a painter...
If we were painters...
If they were painters...

Using the were instead of was sends the message that it whatever we are expressing is not a reality, that it is contrary to fact.