Umlauts or diaereses?
As far as I know (and the OED agrees..), the two little dots themselves are generally called diaeresis. The use of this diacritical sign in German, on a,o and u, is specific for that language. It transforms these vowels into umlauts, meaning that the resulting sound is only slightly resembling the original one. Other languages, e.g. Turkish and Finnish also make liberal use of the sign, but I don't know it's effect on pronounciation there. In combination with e, the effect is diaeresis, also in German. This use is rare to the point of being exotic.
Yes, what wsieber said. The diaeresis is a diacritical mark, and umlaut is etymologically a phonological process (though it is now used in English to refer to the diacritical marks). In German, the sounds transformations are as following: /a/ -> /e/, /o/ -> /ø/, /u/ -> /y/. In addition, the origin of the diaeresis is from a small e placed over the vowel undergoing umlaut. This same process happenes in most Germanic languages: e.g., foot ~ feet, mouse ~ mice, etc. These words were originally two syllable in the plural, and the vocalic sound in the final syllable, which is now gone, modified the vowel in the first syllable.
Umlaut 'umlaut' is from German um- 'about, at' + laut 'sound'. There's a similar phonological process called ablaut 'vowel gradation'. This is the process that shows up as sing ~ sang ~ sung in English and which goes back to PIE.
Nuncle's opinion not withstanding umlaut is a phonological process but
diæresis is, too. It signifies that the vowel so marked is pronounced of itself and is not part of a diphthong. Other languages, e.g., Portuguese call the symbol a trema. That's my vote for the name of the symbol.
Thanks for the replies.
I have a few more questions about diacritics.
Aside from façade, how many words in English require a cedilla?
How many words in English require a tilde, Señor?
What dø yøu call the 'ø' with a diagønal line thrøugh it? When dø yøu use it?
What is the ætiology of the ligature?
Do you think these things are disappearing from English?
HL:
Ignore the man behind the curtain. He knew you meant "commonly used" in English, though you didn't say so explicitly.
The only one I can think of off hand is resume. I am NOT gonna go figure out how to put the little marks over the e's; I am gonna resume reading the other threads.
Well, while reading this over prior to mashing the continue button, I thought of manana. I'll come back tomorrow and put the little mark over the first n.
opinion not withstanding
I suppose I meant that umlaut is a word that describes both an historical phonological process and a diacritical mark used to indicate the modification of a sound (grapheme). I've never heard diaeresis used in this way for the former, but even anglophone linguists use the term umalut in this way to describe how the plural for foot turned out feet and not foots. In fact, umlaut in English is not associated with anything diacritical in the orthography. Adding a diaeresis over the second o in coöperation merely reveals yet another inadequacy of English orthography, not some some bit of phonological history of English. Same with Brontë and résumé, both of which could easily be Bronté and resumë.
As for ligatures, while æ (or ash) and œ have stuck it out, sort of, the long s short s and the ct ligatures have not. There are still fi, fl, and ffl lurking around in some fonts. I believe ligatures are a holdover from MS days, and currently exist in English for aesthetics.
The term cedilla is from the Spanish word for 'little zed' which is the origin of the little mark under the c.
MS is an abbreviation for manuscript. MSS is the plural.