It isn't actually the subjunctive. People often call the "were" of "I wish I were" subjunctive, but that term is much better used (as in The Cambridge Grammar of the English Language) for the construction with "be" seen in "I demand that it be done." The "were" form is often wrongly called a past subjunctive, but of course "it were done" is not a past tense of "it be done". The difference between the two is that the subjunctive construction occurs with any verb: "I demand that this cease" is a subjunctive (notice "this cease", not "this ceases"). The relic form in "I were" is only available for "be". For all other verbs you use the preterite: "I wish I went to New York more often." The Cambridge Grammar calls the "were" form the irrealis form. It is surviving robustly in expressions like "if I were you", but even there it has a universally accepted alternate "if I was you", and there is no semantic distinction there to preserve.
Whether "if I was" and "if I were" are interchangeable for all speakers is unclear. They are for me. However, the argument about the irrealis makes a lot of sense.
Just say it in the way that most native speakers say is not a wrong way.
If they say, If I were you, I would give it a whirl. We should say If I were you.
According to The Oxford Companion to the English Language, "were" is usually used in "if I were you." But in other cases it has been replaced by "was", bringing it in line with other verbs, where the simple past tense is used for expressing hypotheses about the past and future, eg "if I only knew how."
Yes, i agree that we should say as how the native said it.In MALAYSIA, it is common to say If i were you instead of If I was u..If i were you sounds better
According to The Oxford Companion to the English Language, "were" is usually used in "if I were you." But in other cases it has been replaced by "was", bringing it in line with other verbs, where the simple past tense is used for expressing hypotheses about the past and future, eg "if I only knew how."
The "knew" in "if I only knew how" is in the subjunctive. It is just not distinguishable in form from the indicative.
Re: grammar test 
Linear Mode
