umlaut

Linguistics The change, especially an umlaut, that is caused in a sound by its assimilation to another sound.

元变化，变：由于一个被另一个词化而变化，尤其是元变化

Guangdong romanization makes use of diacritics to represent certain vowels.This includes the use of the circumflex, acute accent, and umlaut in the letters ê, é, and ü, respectively.

这一系列拼方案兼容性较差，只能纪录粤语、客家话、闽语某几个方言点，而不能纪录这三种语言大多数方言点。