An 11-year-old British student corrected Justin Bieber's grammar:
In the song, you can be heard - on a number of occasions - stating 'If I was your boyfriend': here you have clearly used the subjunctive mood incorrectly.
The correct lyrics should, in fact, be 'If I were your boyfriend'.
This is a very common mistake made by the general public today; however, if role models (and popular singer/song-writers) such as you cannot use it, why should we make the effort to study and use such grammatical forms correctly?' link
