Mr Pedantic # 46: I would agree that it is probably easiest for learners to opt for the "were" form in standard conditional structures of the "if X were the case, Y would happen" kind, since it will never be "wrong".
5jj: It will not be wrong in hypothetical utterances, but it would be wrong in others. *“If I were out of order, I apologise.” The argument about ‘easiest for learners’ could also apply to the ‘was form
Philo 50: . Of course it is a past tense form (of the indicative mood).
5jj: Not ‘of course’. Most writers refer to it as a past tense form, and it is certainly frequently used to denote past-time situations. However, other tenses are also used to refer to past-time situations, and the ‘past tense’ form can be used to refer to other times.
Philo: Meanwhile - in the absence of any evidence to the contrary - I maintain my assertion that, for most educated AmE users (the majority of the world's native English-speaking populace), hypothetical 'was' is substandard, while it is beyond doubt that no educated speaker of any variety of English would ever reject hypothetical 'were' as ungrammatical!
5jj: There are enough people speaking BrE, and enough wanting to learn it, for us not to have to follow AmE usage in this one instance. Or are you arguing that we should stop using BrE because the majority of English-speakers in the world use AmE?
I don’t think anybody has claimed that hypothetical ‘were’ is ungrammatical. I have questioned the wisdom of teaching a subjunctive mood, which is rather different.
Philo: There is, however, also the argument based on the common sense linguistic principle that potentially ambiguous constructions are naturally less acceptable than unambiguous ones.
5jj: If you are suggesting that ‘if I was you’ is ambiguous, I’d be interested to know in what way it is ambiguous.
There is no ambiguity in such cases such as: If I was a policeman, I would wear a policeman's uniform. However, I am a teacher, so I don’t wear any uniform and Sometimes, I would be a doctor, sometimes a fireman, and sometimes a policeman. If I was a doctor, I would wear a white coat. If I was a fireman, I would wear a fireman's uniform. If I was a policeman, I would wear a policeman's uniform. Context and co-text make the meaning clear.