It is unknown whether non-merpeople who can speak mermish sound the same as merpeople underwater i.e. whether or not they retain an accent (though they probably do) though it is known that non-merpeople can speak it. Dylan Marwood and Albus Dumbledore were known non-Merperson speakers, and Percy Weasley claimed that Barty Crouch Snr could also speak it. Mermish also has a written form, as it was one of the seventy-two languages that Miranda Goshawk's Book of Spells was published in. Though it is not specific, we can assume that Mermish originated from the Greek coasts, as that is where the first Mermish settlements were. Mermish is a curious language that is specifically adapted for use underwater. When underwater it sounds much like English, or perhaps even like any other language however, out of water the language changes to a screeching, harsh and raspy sound.