If you are lucky (or unlucky) enough to speak Parseltongue, you have the ability to communicate with snakes. Salazar Slytherin was one very famous Parselmouth – it’s why Slytherin’s symbol is a serpent! However, as Harry (another Parselmouth) found out, it’s a language which is often regarded with suspicion and seen as the mark of a Dark wizard. In some ways that could make sense, as Voldemort was someone who could communicate with snakes, as well as being a descendent of Slytherin. Although, as Harry demonstrates, not all those who speak this language are bound to do Dark deeds.
Goblins have a long and complicated history in the wizarding world – from their many rebellions to working at Gringotts bank. But did you know that they had their own language, Gobbledegook? It was one of over two hundred languages that Barty Crouch spoke. Which is much more impressive than Ludo Bagman who only knew the Gobbledegook word for pickaxe – which is Bladvak if you were wondering.
According to Fred Weasley anyone can speak Troll – it’s just a case of pointing and grunting at things. He doesn’t seem to be wrong. According to Newt Scamander’s Fantastic Beasts and Where to Find Them, trolls seem to have a crude language made up of mainly (you guessed it) grunts. Though they have also been known to be able to understand and even speak a few human words. But as creatures of rather limited intelligence… there is only so much they can comprehend.
This is another language in Barty Crouch’s repertoire – and one in Albus Dumbledore’s too! Mermish in the language spoken by merpeople. One interesting fact is that merpeople’s voices sound different when above the water and under it. Underneath, they speak in what sounds like a human language (the merpeople in the lake at Hogwarts appear to speak English). But when they are out of the water their voices suddenly sound completely different – and rather unpleasant. As Harry learnt when he opened the Golden Egg above water in Goblet of Fire, when merpeople aren’t in water they sound as though they are screeching and caterwauling.
If you look closely Runes appear throughout the Harry Potter series in one form or another. For instance, Ancient Runes was one of the many subjects that Hermione Granger studied and excelled at (even if she got the words ehwaz and eihwaz mixed up in her O.W.L.). Runes were also found inscribed around the Pensieve in Dumbledore’s office. And after his death, Dumbledore left a copy of The Tales of Beedle the Bard to Hermione that were all written in these curious symbols. It’s a shame that Harry never learnt to read them himself – as they crop up rather frequently.