Question and Answer in an online site
[Q] Which is grammatically correct: "I wish I were you" or "I wish I was you"?
![Angel [A]](/emoticons/emotion-13.gif)
Older, prescriptive grammar books insist on the use of the subjunctive form "were". Most modern, descriptive grammar books accept both "were" and "was" as being grammatically acceptable, but they suggest that "I wish I were" is more appropriate in formal contexts.
My opinion:
Each ESL student has their own purpose of learning English. If your purpose is just to talk with native speakers, you can use "I wish I was". But if you want to study something by reading books or other forms of formal documents written in English, it would be better you learn "I wish I were" is more appropriate, because writers of such a document mostly have used and still are using "I wish I were" in their writing.
paco