Since the Abyss has countless layers and inhabited by Chaotic and very uncooperative creatures, Abyssal inevitably spawns lots of dialects, that constantly diverge (and borrow from each other and everywhere else). Which is why the locals tend to be misunderstood often. This only adds to their habitually foul attitude, of course. IIRC this was in Faces of Evil.
People never wonder How the world goes round -Helloween And even I make no pretense Of having more than common sense -R.W.Wood It's not good, Eric. It's a gazebo. -Ed Whitchurch