A 11-year-old boy has pointed out a grammatical error in singer Justin Bieber's song "Boyfriend".

The boy particularly takes issue with the line, "If I was your boyfriend, I'd never let you go". 

In his letter, posted on Facebook by his teacher, he pointed out that the specific lyric "used subjunctive mood incorrectly", reports aceshowbiz.com. 

"The correct lyrics should, in fact be, 'If I were your boyfriend.' This is a very common mistake made by the general public today," he continued. 

"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?" 

The boy added that he is disappointed that Bieber is "unable to follow what is considered to be the basics of the English language". 

He told the "Baby" hitmaker to learn a thing or two from fellow singer Beyonce Knowles. 

"If current performers, such as Beyonce can write a song using the subjunctive mood correctly, so must you," he concluded.