The Daily Mirror reports that a British schoolboy has written a letter to Justin Bieber complaining about his poor grammar. The singer was told by the 11-year-old that he must 'use the subjunctive mood correctly in future' after failing to do so in his 2012 hit Boyfriend. The letter says: "If current performers, such as Beyonce can write a song using the subjunctive mood correctly, so must you." Full article >>
There are many things that Justin Bieber can be criticized for, but in this case he's probably been unfairly accused. As this Quora post points out:
Yes, grammatical strictness indicates that "if I were" is usually correct and should be used. However, not only does "if I was" often go unnoticed, it's also used much more often. "If I was" gets 1.7 trillion hits on Google vs. 110 million for "if I were." This is one of those cases where incorrect grammar has become so prevalent that it's worth considering that it may become officially accepted at some point.
I would also add that in song lyrics, it's generally accepted that the normal rules of grammar don't apply. "There isn't any sunshine when you're gone" doesn't sound quite the same as "Ain't no sunshine when you're gone." And if Mick Jagger had sung "I can't get any satisfaction" rather than "I can't get no satisfaction", would the Stones have had such a big hit? Having said that, you should definitely avoid saying "If I was you", which does sound wrong.