Sometimes you would see two dots above some vowels, like Joyeux Noël (French for Merry Christmas), or naïve in, curiously, English. This diacritic can be found in alphabets from Albanian to Swedish. Normally represented by two dots above the letter where the sound is modified, or some other things, we also find a similar-looking sort of diacritic used in languages like German, Swedish, and Finnish. They all appear the same, yet have different origins. So how did these converge into the diacritic we are generally familiar with today?

Diaresis & Tréma

The diaresis and the tréma actually do mean the same thing, but have different word origins. They are otherwise used interchangeably, although the diaresis seems to be more commonly used in English, while the tréma is more often used in French. Interestingly, these words stem from the same language, Greek, but have two separate meanings. Diaresis comes from the word διαίρεσις, which means “division” or “separation”, while tréma comes from τρῆμα, which means “perforation” or “a die pip”. While the latter suggests the function of the diacritic, the latter references the dotted appearance of the diacritic on the letter it is attached to.

As the former suggests, the diaresis indicates a separation of two distinct vowels in adjacent syllables, distinguish it from a digraph or a diphthong. Although almost absent in English, it is regularly used in languages such as French, Dutch, Greek, and interestingly, German as well.

How did this come about? It turns out, that this actually has a lot to do with the Greek language, as if the name has not suggested it already.

During the Hellenistic period, the diaresis started appearing on the letters ι and υ typically at the start of the word, which were meant to separate them from a preceding vowel. This was because the spacebar was not invented yet, and neither was spacing between words that divide a whole chunk of letters into individual words. However, in addition to this, it also signaled that a vowel formed its own syllable, rather than being part of a diphthong.

It was the latter function that fueled the rise of the diaresis in languages across Europe, and some languages on the continent started to take this even further, using this diacritic whenever a vowel letter was meant to be pronounced separately. This sort of explains the spelling pingüino in Spanish to mean “penguin”, since Spanish, like many other Romance languages, uses a “gu” to represent the “g” sound if it is followed by the vowels “i” or “e”. If spelt pinguino, it would have been pronounced something similar to “ping-gino” rather than “ping-gwino”. Similar patterns are observed in languages like Dutch, Afrikaans, Luxembourgish, French, Guarani, and Catalan.

Despite the pervasive use of the umlaut in German, the diaresis is actually used, particularly on the letter “e”, to distinguish words, particularly proper names, which have vowels that would otherwise appear as a digraph. An example of this is Piëch, which has two syllables, pronounced as pi-ech. If the diaresis is absent, this word would have only one syllable and pronounced as Piech, with a long-i vowel. Another example contrasts the separation between syllables with vowel fronting which is not indicated by the umlaut. Consider Hoëcker, which has three syllables ho-e-ker, and contrast this with Goethe, which has two syllables, and the “oe” diagraph represents the vowel [øː], the same sound as the o-umlaut ӧ.

Umlaut

The umlaut marks a sound shift in a vowel, where a back vowel becomes a front vowel (that is, based on where it is sort of articulated in the mouth or tongue). But it did not always use the two dots we see today.

In Germanic languages, using German as an example here, vowel fronting is a phenomenon of rather significance in the language’s history. The phonemes [a], [aː], [ɔ], [oː], [ʊ], [uː] and diphthong [aʊ] to shift forward in the mouth to [ɛ], [ɛː] (or, for many speakers, [eː], resulting in a merger with /eː/), [œ], [øː], [ʏ], [yː] and [ɔʏ], respectively.

So how did this originally get represented in writing? Well, this used to be done by writing the letter “e” right after the vowel affected by the sound change. This is still seen today in names like Goethe, and the stationery manufacturing company Staedtler. In some manuscripts, however, this “e” was written as a superscript, above the affected letter.

But over time, in manuscript handwriting, this letter “e” became two dots. Sometimes, this is closer towards two short vertical lines, or as two tiny strokes. It is unclear how or when this occurred, but it is likely that this took place some time when Middle German or Early Modern German was used (High German, that is).

This diacritic was later borrowed in the orthographies of other languages like Hungarian, which went further to create diacritics for long vowels, using the double acute accent as in ő. These generally represent similar sounds to those we hear in German, or at least, parallel the German sounds. A similar umlaut system could be found in the Cyrillic alphabet, used by languages such as Mari and Khanty. These are represented by ӓ, ӧ, and ӱ, and parallels the corresponding sounds used in German.

Of course, we have other languages that use the diaresis for unrelated uses. Take Albanian for example, which uses the letter ë to represent the schwa sound. Additionally, the diaresis is also used in a more stylistic sense, as with the Brontë family. In pop culture, the metal umlaut is also used decoratively in the names of rock or metal band names, possibly to invoke a gothic horror connotation to it. It does not, however, alter the vowel sound in any way.

The use of either diacritic in Modern English is extremely rare, with the diaresis being used in words like “naïve”, the constellation “Boötes”, and “Noël”. Sometimes one would find the diacritic in names like Chloë and Zoë, but for words like “coöperate” and “reënter”, the diacritic’s use is pretty much rendered archaic.