Hi there, there’s a #language and an #accents tag that that addresses what the accents sound like! As for how the languages sound compared to Common:
Kettish: Kettish, to an outside ear, tends to sound more clipped and precise in tone, with both hard, sharp stops (hata'ki, meaning neurotic) and some flowing, more fluid sounds (mythas, galvorn-aith and megil-aith). It tends to sound more moderate and even in tone, often slow and careful (depending on the speaker and their background) or even flat, but it is also a pitch accent language where occasional subtle drops or raises in tone on a syllable can sometimes change a word’s meaning–just not as systematically or extensively as an actual tonal language (like Mandarin or Vietnamese).
Uth: Uth, the Hunter ancestral language, is extremely guttural and throaty, emanating from the back of the throat. It tends to sound very harsh to outsiders, forceful and somewhat short, with a strong emphasis on raspy, rumbled growls, barked, punchy commands, or tight, constricted sounds. Like the Hunter exorcist arts, a lot of it is shaped by breath and vibration. So it can sound deep, harsh, tight, or forceful; sometimes it will sound to outsiders like Hunters are mad or arguing with each other when they’re really just talking! It’s also one of the simplest ancient languages out there, with a more limited vocabulary that is heavily dependent on context, which is why so many Hunters also grow up speaking Common or use it as their default/first language instead of Uth (the same goes with Kettish). It just tends to be easier to express oneself in Common because there are more ready-made words for complex concepts!
Elvish: highly musical and lyrical, flowing, airy, and (you nailed it) often described as silvery. It’s frequently compared to the sound of running water or wind through grass. It lends itself very well to music and poetry, has a smooth cadence with few harsh stops, and tends to sound soothing and fluid to listen to. It also has the broadest vocabulary of any known language, which leads many scholars to believe it was the Continent’s earliest mother tongue. Even its hard stops tend to be softened–the word taika (which you can look up in the Glossary, as it’s a pretty lore-interesting one) is very soft, to the point where you don’t really hear the click of the ‘k’ when a natural Elvish speaker uses it, if that makes any sense. Although it’s not a tonal language in that changes in tone alters the meaning of the actual word, tone is still extremely important in Elvish speech when it comes to social and cultural cues (kind of like avoiding asking direct questions to elders because it’s seen as impolite), making it one of the hardest languages to master for an outsider.
Magid: Magid isn’t used as a spoken language anymore and tends to only be read as a written script consisting of complex runes and hieroglyphics: it would sort of be like speaking Ancient Latin, or Sanskrit, or Abyssinian, or any dead language like Ancient Greek, where there aren’t really native speakers but people who can learn how to understand and piece together the written language through study (primarily for casting magic). Part of the reason why it fell out of use/experienced such drastic linguistic drift was because it had ridiculously complicated grammatical rules, where you could add on an endless amount of syllables or compound words to a base word in order to change its meaning, so instead of “Valeth orum kael” (“Where is tool?”) it’d become like “Valethorummelanka'elsheth” (“Where are my tools, that you were last seen holding?”). Something like that. I like to headcanon that this is where the tradition of Mages with long, wordy names that they truncate into shorter nicknames (Panrachus -> Pan, Saleneon -> Neon, Liefred -> Red) came from!
Costa: Costa, the language of the southern isles and the coasts, tends to be very sing-song, warm, animated, lilting, and bombastic. It’s expressive and musical, with wide pitch variation and rolling vowels that rise and fall dramatically across a sentence. Speech in Costa might sound almost performative to a Common-speaking outsider: it’s really bombastic, emotive, and rhythm-driven, with every conversation sounding like a really exciting story or passionate declaration, lol. It’s full of confidence and tends to carry easily over distances and crowds, which is why a lot of seafarers use it!
Korkyth: Korkyth is blunt and weighty and thick and curdling, very dense and heavy. It’s kind of similar to Uth, their being from the same region, but Korkyth tends to be slow and rolling, almost like molasses or syrup, whereas Uth tends to be sharper and more glottal. However, they’re both deeper, low languages and almost so practical as to sound simplistic. Some outsiders might think of Korkyth as sort of slurring together; it doesn’t use a lot of differentiating tones to distinguish words from each other.
Gangara: Gangara is bright, fast, confident, and jabby, relying a lot on speed and rhythm to convey meaning. It favors quick, jabby consonants and tight phrasing, giving it a sense of momentum and verbal sharpness. To outsiders, it often sounds energetic and confrontational, even when the speaker isn’t being hostile at all, or like a constant back-and-forth bargaining/haggling exchange going on, kind of playful but also assertive, if that makes any sense? Two speakers speaking in Gangara usually talk like they’re trading punches. There’s a confident, declarative rhythm to it, a lot of emphatic verb punch packed into short phrases, and crisp, percussive consonants. It’s sort of brassy and blaring, like a trumpet!
Thanks for your question, hope that was interesting to read!