How do sound changes operate in languages that have vowel harmony? Do Do they change with the vowels and thus create myriad words based on the different forms that it can take on based on affixes? I am simply confused as to this.

Another question to add on, is how does it work with agglutinative languages in general, as to remain agglutinative and not just have the forms become a long list of individual, unique words?

2 Answers 2


One well-known example is the changes to vowel harmony in Korean, from the Middle Korean period (13th-15th centuries) to the modern day.

In Late Middle Korean, the yang/bright vowels were ㅏ /a/, ㆍ /ʌ/ and ㅗ /o/, while the yin/dark vowels were ㅓ /ə/, ㅜ /u/, and ㅡ /ɨ/. The vowel ㅣ /i/ was neutral. There is some debate on the precise realisations of these vowels, but the vowel harmony itself is consistent.

There have been many vowel shifts that have happened to [Seoul] Korean since then, with ㅓ /ə/ moving towards /ɔ/, ㅗ /o/ becoming closer to /u/, and ㅜ /u/ fronting to /ʉ/, not to mention what's happened with compound vowels. But overall, these changes did not hugely affect the pattern of vowel harmony in verb conjugations or in word derivations. Indeed, Modern Standard Korean retains vowel harmony in certain verb forms, even though the 21st centuy sound of ㅓ may be very different to what it was in the 16th century (and potentially closer to what the 15th century yang vowel ㆍ used to be).

However, the complete loss of the vowel arae a ㆍ /ʌ/ as well as the increased use of non-harmonising loanwords (mainly from Late Middle Chinese) dramatically eroded productive vowel harmony. This is especially relevant in nominal morphonology, where ㆍ was used in the yang forms of many particles.


"Cat" and "cats", "dog" and "dogs" are two separate words, but you can derive "cats" from "cat" by applying a rule. The same holds for languages with vowel harmony. If (like in Turkish) there is a suffix that changes depending on what it is added to, you just learn the roots and affixes, plus the rules.

But sometimes the child cannot figure out the affixes or roots, or the rules, because they have become too irregular from a certain learning perspective, then the child may have to learn separate words, like "child" and "children". The same thing holds for vowel harmony: the question reduces to whether the child can figure out a system. Where vowel harmony gets somewhat complicated is that if you have a suffix pronounced ti, tu, ty, tɨ then you may have to work hard to figure out what the underlying form of the suffix is, and sometimes because of converging sound changes (for example progressive vowel height harmony in Logoori but also word-final vowel-raising), you end up with seemingly "wrong" vowel changes, which happen when speakers re-analyze the suffix /e/ as /ɪ/.

Vowel harmony is a factor that can lead to confusion as to what affix does with what context, but it's not really a special thing about vowel harmony. What is somewhat special about vowel harmony is that the thing causing the change is phonetically more remote – it's not just the immediately preceding or immediately following segment, as is the case with nasal assimilations for instance.

  • 1
    I’m not entirely sure I’ve correctly understood the question, but I think it’s asking about historical vowel change and how that interacts with vowel harmony. For example, imagine a language that has front and back-vowel harmony so a suffix may have allophones /tu/ and /ty/. Now say this language undergoes a very common change that turns (back) /a/ into (front) /ɛ/ – what happens with the vowel harmony? Does haga-tu become hɛɡɛ-tu or hɛɡɛ-ty? At least I think that’s what (the first part of) the question is asking about… Apr 19, 2021 at 19:17
  • What I mean is like, for example, lets say a word Hagu, and add the suffix -mu, making Hugumu, and vowel change occurs alongside this, what would happen? Would Hugumu become its own word? Or would only the original Hagu form change>
    – Zoey
    Apr 20, 2021 at 1:04

This site is temporarily in read-only mode and not accepting new answers.

Not the answer you're looking for? Browse other questions tagged .