It's become a stereotype that Asians mix up the R and L sound when speaking English. That's a minor problem compared to the weird sounds coming from English speakers who attempt, but don't quite get, Asian tonal languages. But when you break down the linguistics, the R sound is very complicated, and so is the L, and native speakers of different languages learn to pronounce it differently from each other, and differently within languages depending on where it falls within a word. How complicated can it be? Joss Fong of Vox explains.