Spoken Korean used to have some tones until the 1500s, then lost them. In written Hangul (the original 1400s version) the tones were indicated with a dot diacritic to the left of the character.
It's not known if Hangul influenced the dropping of tones from the spoken language or not, but around the 1500s and into the 1600s tones started being omitted in written Hangul (probably to make it faster to write, like dropping vowel diacritics from Arabic). Hangul also lost some letters and there's been some vowel shift with two different vowels (애 and 에) nearly merging today.
Like in Japanese, it appears the Korean tone system was replaced with a length system to help identify homophones, which lasted until very recently. My understanding is it's still formerly part of the language (and is taught in grade school with this rule), but most Koreans don't really use it anymore.
I think today you still hear vestiges of tone in Spoken Korean but it's more used as part of the phrasing and is distinct from statement/question tone changes like in English. You can hear it in longer conversational Korean like here: https://www.youtube.com/watch?v=RMnp3efz6s4
It's not known if Hangul influenced the dropping of tones from the spoken language or not, but around the 1500s and into the 1600s tones started being omitted in written Hangul (probably to make it faster to write, like dropping vowel diacritics from Arabic). Hangul also lost some letters and there's been some vowel shift with two different vowels (애 and 에) nearly merging today.
Like in Japanese, it appears the Korean tone system was replaced with a length system to help identify homophones, which lasted until very recently. My understanding is it's still formerly part of the language (and is taught in grade school with this rule), but most Koreans don't really use it anymore.
http://askakorean.blogspot.com/2014/01/tonal-vestige-in-kore...
I think today you still hear vestiges of tone in Spoken Korean but it's more used as part of the phrasing and is distinct from statement/question tone changes like in English. You can hear it in longer conversational Korean like here: https://www.youtube.com/watch?v=RMnp3efz6s4