Also present in Altaic languages like Turkish, for 10 points, name this feature of languages in which the vowels of a word assimilate to be only of one type.
Haruo Aoki proposed three criteria for this and rejected two in an article entitled "Toward a Typology of" this, while a book by Martin Kr?er on this feature describes some certain phonemes as Trojan, hybrid, opaque, or transparent. Arisaka's Laws indicate that Old Japanese may have had a form of this feature. Guaran?has a form analogous to this one with nasals, and Germanic umlaut was a weaker form of this phenomenon. It is often determined by height, backness, or roundedness of the phonemes at hand, and can occur progressively or regressively, often affecting suffixes, as in Hungarian. Estonian has notably lost this feature, while Finnish retains it, classifying /i/ and /e/ as neutral. Also present in Altaic languages like Turkish, for 10 points, name this feature of languages in which the vowels of a word assimilate to be only of one type.
Haruo Aoki proposed three criteria for this and rejected two in an article entitled "Toward a Typology of" this, while a book by Martin Kr?er on this feature describes some certain phonemes as Trojan, hybrid, opaque, or transparent.
vowel harmony [prompt on assimilation of vowels]