Diaeresis (diacritic)
The
diaeresis ,
trema or
umlaut is a diacritic that consists of two dots placed over a letter, most commonly a vowel. When that letter is an
i or a
j, the diacritic replaces the tittle:
ï.
Diaereis and the
umlaut are diacritics marking two distinct phonological phenomena. The diaeresis represents the phenomenon also known as
diaeresis, or
hiatus, in which a vowel letter is
not pronounced as part of a digraph or diphthong. The
umlaut, in contrast, indicates a sound shift. These two diacritics originated separately; the diaeresis is considerably older. Nevertheless, in modern computer systems using Unicode, the umlaut and diaeresis diacritics are identical: 〈
ä〉 represents both a-umlaut and a-diae symbol is also used as a diacritic in other cases, distinct from both diaeresis and umlaut. For example, in Albanian,
ë represents a schwa.