Whether they're proving themselves worthy of an international fanbase or avoiding the paparazzi, most celebrities can slip on a fake accent with complete confidence. Unfortunately (and fortunately for us!), others seem to falter. Watch Justin Bieber, Beyoncé, the Harry Potter stars and other celebrities test their dialect coaching in this week's video compilation.

Featuring videos via BBC | itn | HannahFanMiley11 | snowluv4 | BBC Worldwide | joeadams823 | hollywoodtv | T4