refers to is the diaeresis
, from the Greek
for `to divide
'; or, in French, trema
. The use of the diaeresis in English is disappearing, especially in America
(how often do you see the word `coöperate
' anymore?). It is still common in French
, and other more phonetic language
s. (Yes, I am calling French `phonetic'. Deal.
`Umlaut' (see the Webster 1913 definition below) refers to the sound change the symbol represents. Umlaut as it occurs in Germanic langauges generally causes a back vowel to become fronter, and often higher.
See also ablaut, a different kind of vowel shift that is less patently Germanic (but is still patently Indo-European).