Vowel harmony is part of what make Korean sound so lovely to my ears. I can't describe it well. Some vowels as "dark" and some are "light", and the way Koreans make words takes this into account.
In part, this is because of how we make the sound of "light" vs. "dark" vowels. It would be hard to make the sound of switching from light to dark vowels in the same word.
Positive/"light Vowels ㅏ (a)ㅑ (ya) ㅗ (o) ㅘ (wa) ㅛ (yo)
Negative/"dark Vowels ㅓ (eo)ㅕ (ye/) ㅜ (u) ㅝ (wo) ㅠ (yu) ㅔ (e)
See Wikipedia for full explanation
9 years ago