View source for Two dots (diacritic)

{{short description|Diacritic that consists of two dots placed over a letter}}
{{redirects|Tréma||Trema (disambiguation){{!}}Trema}}
{{Infobox diacritic|char=◌̈&nbsp;◌̤
|name=Two dots
|unicode={{ubl
|{{Unichar|0308|COMBINING DIAERESIS|cwith=◌|html=}}{{efn|The diacritic is referred to in Unicode as a [[diaeresis (diacritic)|diaeresis]], without distinction, although the term has a [[diaeresis (prosody)|more precise literary meaning]].}}
|{{unichar|0324|Combining diaeresis below|cwith=◌|html=}}
|{{unichar|07F3|NKO combining double dot above|nlink=N'Ko script#Non-native sounds and letters}}
}}}}
{{Orthography notation}}
[[Diacritical mark]]s of '''two dots''' '''{{char|¨}}''', placed side-by-side over or under a letter, are used in several languages for several different purposes. The most familiar to [[English language|English-language]] speakers are the [[Diaeresis (diacritic)|diaeresis]] and the [[Umlaut (diacritic)|umlaut]], though there are numerous others. For example, in [[Albanian language|Albanian]], {{char|ë}} represents a [[schwa]]. Such diacritics are also sometimes used for stylistic reasons (as in the family name [[Brontë family|Brontë]] or the band name [[Mötley Crüe]]).

In modern computer systems using [[Unicode]], the two-dot diacritics are almost always [[character encoding|encoded]] identically, having the same [[code point]].<ref name=Unicode5.0>{{cite book |title=The Unicode Standard v 5.0 |date=2006 |publisher=Addison-Wesley |location=San Francisco |isbn=0-321-48091-0 |pages=228}}</ref> For example, {{unichar|00F6|LATIN SMALL LETTER O WITH DIAERESIS}} represents both ''o-umlaut'' and ''o-diaeresis''. Their appearance in print or on screen may vary between [[typeface]]s but rarely within the same typeface.

The word ''[[wikt:trema|trema]]'' ({{langx|fr|tréma}}), used in linguistics and also [[Classics|classical scholarship]], describes the form of both the umlaut diacritic and the diaeresis rather than their function and is used in those contexts to refer to either.

==Uses==
===Diaeresis===
{{main article|Diaeresis (diacritic)}}
As the "diaeresis" diacritic, it is used to mark the separation of two distinct vowels in adjacent syllables when an instance of [[Hiatus (linguistics)|diaeresis (or hiatus)]] occurs, so as to distinguish from a [[digraph (orthography)|digraph]] or [[diphthong]]. For example, in the obsolete spelling "coöperate", the diaeresis reminded the reader that the word has four syllables ''co-op-er-ate'', not three. It is used in several languages of western and southern Europe, though rarely now in English.<ref>{{cite web |url=http://dscriber.com/news/121-the-new-yorkers-odd-mark-the-diaeresis|archive-url=https://web.archive.org/web/20101216160024/http://dscriber.com/news/121-the-new-yorkers-odd-mark-the-diaeresis |first= Dan |last=Baum |series=Trade Secrets | website=Dscriber |url-status=dead|archive-date=16 December 2010|title=The New Yorker's odd mark — the diaeresis|date=16 December 2010 |quote=Among the many mysteries of The New Yorker is that funny little umlaut over words like coöperate and reëlect. The New Yorker seems to be the only publication on the planet that uses it, and I always found it a little pretentious until I did some research. Turns out, it's not an umlaut. It's a diaeresis.}}</ref> One well-known usage is in [[French language|French]] - the diaeresis is used in naïve, which is commonly spelled in English without the diaeresis. It is, however, obligatory in French, to show that it is pronounced [na.iv] rather than [nev].

===Umlaut===
{{main article|Umlaut (diacritic)}}
As the "umlaut" diacritic, it indicates a [[sound shift]] {{snd}} also known as [[Umlaut (linguistics)|umlaut]]{{snd}} in which a [[back vowel]] becomes a [[front vowel]]. It is a specific feature of [[German language|German]] and other Germanic languages, affecting the graphemes {{angle bracket|a}}, {{angle bracket|o}}, {{angle bracket|u}} and {{angle bracket|au}}, which are modified to {{angle bracket|[[ä]]}}, {{angle bracket|[[ö]]}}, {{angle bracket|[[ü]]}} and {{angle bracket|äu}}.

It can be seen in the [[Sutterlin]] script, formerly used widely in German handwriting, in which the letter ''e'' is formed as two short parallel vertical lines very close together (see under [[Sütterlin#Characteristics]]).

===Stylistic use===
The two dot diacritic is also sometimes used for purely stylistic reasons. For example, the [[Brontë family]], whose surname was derived from [[Irish Gaelic|Gaelic]] and had been [[Anglicisation|anglicised]] as "Prunty", or "Brunty": At some point, the father of the sisters, [[Patrick Brontë]] (born Brunty), decided on the alternative spelling with a diaeresis diacritic over the terminal {{angbr|e}} to indicate that the name had two syllables.

Similarly the "[[metal umlaut]]" is a diacritic that is sometimes used gratuitously or decoratively over letters in the names of [[hard rock]] or [[heavy metal music|heavy metal]] bands{{snd}}for example, those of [[Motörhead]] and [[Mötley Crüe]], and of parody bands, such as [[Spinal Tap (band)|Spın̈al Tap]].

===Other uses by language===
A double dot is also used as a diacritic in cases where it functions as neither a diaeresis nor an umlaut. In the [[International Phonetic Alphabet]] (IPA), a double dot above a letter is used for a [[Centralization (phonetics)|centralized vowel]], a situation more similar to umlaut than to diaeresis. In other languages it is used for vowel length, nasalization, tone, and various other uses where diaeresis or umlaut was available typographically. The IPA uses a double dot below a letter to indicate [[Breathy voice|breathy (murmured) voice]].<ref name="IPA below">{{cite book |title=Handbook of the International Phonetic Association : a guide to the use of the International Phonetic Alphabet |isbn=9780521652360 |location=Cambridge |publisher=Cambridge University Press |date=2021 |last=International Phonetic Association}}.</ref>{{efn|The ''IPA Handbook'' calls the mark "subscript umlaut", in contrast with the [[Unicode Consortium]]'s choice of "diaeresis below".}}

====Vowels====
* In [[Albanian language|Albanian]], [[Tagalog language|Tagalog]], [[Kashubian language|Kashubian]], and [[Luxembourgish]] {{angle bracket|ë}} represents a [[schwa]] [ə].
* In [[Aymara language|Aymara]], a double dot is used on {{angle bracket|ä}} {{angle bracket|ï}} {{angle bracket|ü}} for [[vowel length]].
* In the Basque dialect of Soule, {{angle bracket|ü}} represents {{IPA|[y]}}
* In the DMG romanization of [[Tunisian Arabic]], {{angle bracket|ä}}, {{angle bracket|ö}}, {{angle bracket|ṏ}}, {{angle bracket|ü}}, and {{angle bracket|ṻ}} represent {{IPA|[æ]}}, {{IPA|[œ]}}, {{IPA|[œ̃]}}, {{IPA|[y]}}, and {{IPA|[y:]}}.
* In [[Ligurian (Romance language)|Ligurian]] official orthography, {{angle bracket|ö}} is used to represent the sound {{IPA|[oː]}}.
* In [[Māori language|Māori]], a diaeresis (e.g. {{lang|mi|wähine}}) was often used on computers in the past instead of the [[Macron (diacritic)|macron]] to indicate long vowels, as the diaeresis was relatively easy to produce on many systems, and the macron difficult or impossible.<ref name="macrons">{{cite web |url=http://www.tetaurawhiri.govt.nz/english/pub_e/conventions3.shtml#Part_One_ |title=Māori Orthographic Conventions |publisher=Māori Language Commission |archive-url=https://web.archive.org/web/20090906110915/http://www.tetaurawhiri.govt.nz/english/pub_e/conventions3.shtml#Part_One_ |access-date=11 June 2010|archive-date=2009-09-06 }}</ref><ref>{{cite encyclopedia |url=http://www.teara.govt.nz/en/matauranga-hangarau-information-technology/3 |title=Māori language on the internet |encyclopedia =[[Te Ara: The Encyclopedia of New Zealand]]}}</ref>
* In [[Seneca language|Seneca]], {{angle bracket|ë}} {{angle bracket|ö}} are [[nasal vowel]]s, though {{angle bracket|ä}} is {{IPA|[ɛ]}}, as in German umlaut. 
* In [[Vurës language|Vurës]] (Vanuatu), {{angle bracket|ë}} and {{angle bracket|ö}} encode respectively {{IPA|[œ]}} and {{IPA|[ø]}}.
* In the [[Pahawh Hmong]] script, a double dot is used as one of several tone marks.
* The double dot was used in the [[early Cyrillic alphabet]], which was used to write [[Old Church Slavonic]]. The modern [[Cyrillic]] [[Belarusian alphabet|Belarusian]] and [[Russian alphabet|Russian]] alphabets include the letter {{angle bracket|ё}} (''[[Yo (Cyrillic)|yo]]''), although replacing it with the letter {{angle bracket|[[е]]}} without the diacritic is allowed in Russian.
* Since the 1870s, {{angbr|Ї}}, {{angbr|ї}} ([[Yi (Cyrillic)|Cyrillic letter ''yi'']]) has been used in the [[Ukrainian alphabet]] for [[iotated]] {{IPA|[ji]}}; plain [[і]] is not iotated {{IPA|[i]}}. In [[Udmurt language|Udmurt]], [[ӥ]] is used for uniotated {{IPA|[i]}}, with [[и]] for iotated {{IPA|[ji]}}.
* The form {{angbr|ÿ}} is common in [[Dutch orthography|Dutch]] handwriting and also occasionally used in printed text – but is a form of [[IJ (digraph)|the digraph "ij"]] rather than a modification of the letter {{angbr|y}}.
* [[Komi language|Komi]] and [[Udmurt language|Udmurt]] use {{angle bracket|[[O with diaeresis (Cyrillic)|Ӧ]]}} (a Cyrillic O with two dots) for [[Mid central vowel|{{IPA|[ə]|cat=no}}]].
* The [[Swedish language|Swedish]], [[Finnish language|Finnish]] and [[Estonian language|Estonian]] languages use {{angle bracket|[[Ä]]}} and {{angle bracket|[[Ö]]}} to represent [[Near-open front unrounded vowel|{{IPA|[æ]|cat=no}}]] and [[Mid front unrounded vowel|{{IPA|[ø]|cat=no}}]]
* In the languages of [[J.R.R. Tolkien]]'s ''[[Middle-Earth]]'' novels, a diaeresis is used to separate vowels belonging to different syllables (e.g. in ''[[Eärendil]]'') and on final e to mark it as ''not'' a [[schwa]] or silent (e.g. in ''[[Manwë (Middle-earth)|Manwë]]'', ''[[Aulë]]'', ''[[Oromë]]'', etc.). (There is no schwa in these languages but Tolkien wanted to make sure that readers wouldn't mistakenly pronounce one when speaking the names aloud.){{cn|date=November 2022}}

====Consonants==== <!-- this section is linked from [[Template:Letters with umlaut]] -->
[[Jacaltec]] (a [[Mayan languages|Mayan]] language) and [[Malagasy language|Malagasy]] are among the very few languages with a double dot on the letter "n"; in both, [[n̈]] is the [[velar nasal]] {{IPA|[ŋ]}}.

In [[Udmurt language|Udmurt]], a double dot is also used with the consonant letters [[ӝ]] {{IPA|[dʒ]}} (from ж {{IPA|[ʒ]}}), [[ӟ]] {{IPA|[dʑ]}} (from з {{IPA|[z] ~ [ʑ]}}) and [[ӵ]] {{IPA|[tʃ]}} (from ч {{IPA|[tɕ]}}).

When distinction is important, [[Ḧ]] and [[ẍ]] are used for representing {{IPA|[ħ]}} and {{IPA|[ɣ]}} in the Kurdish [[Kurmanji alphabet]] (which are otherwise represented by "h" and "x"). These sounds are borrowed from Arabic.

[[Ẅ]] and [[ÿ]]: ''Ÿ'' is generally a vowel, but it is used as the (semi-vowel) consonant {{IPA|[ɰ]}} (a {{IPA|[w]}} without the use of the lips) in [[Tlingit language|Tlingit]]. This sound is also found in [[Coast Tsimshian]], where it is written [[ẅ]].

A number of languages in [[Vanuatu]] use double dots on consonants, to represent [[Linguolabial consonant|linguolabial]] (or "apicolabial") phonemes in their orthography. Thus [[Araki language#Consonants|Araki]] contrasts bilabial ''p'' {{IPA|[p]}} with linguolabial ''p̈'' {{IPA|[t̼]}}; bilabial ''m'' {{IPA|[m]}} with linguolabial ''m̈'' {{IPA|[n̼]}}; and bilabial ''v'' {{IPA|[β]}} with linguolabial ''v̈'' {{IPA|[ð̼]}}.

[[Seneca language|Seneca]] uses {{angle bracket|s̈}} for {{IPA|[ʃ]}}.

In [[Arabic]] the letter [[ẗ]] is used in the [[ISO 233]] transliteration for the [[tāʾ marbūṭah]] [ة], used to mark feminine gender in nouns and adjectives.

[[Syriac language|Syriac]] uses a two dots above a letter, called [[Siyame]], to indicate that the word should be understood as plural. For instance, {{lang|SYC|ܒܝܬܐ}} ({{transliteration|SYC|bayta}}) means "house", while {{lang|SYC|ܒܝ̈ܬܐ}} ({{transliteration|SYC|bayte}}) means "houses". The sign is used especially when no vowel marks are present, which could differentiate between the two forms. Although the origin of the [[Siyame]] is different from that of the diaeresis sign, in modern computer systems both are represented by the same Unicode character. This, however, often leads to wrong rendering of the Syriac text.

The [[N'Ko script]], used to write the [[Mande languages|Mandé languages]] of [[West Africa]] uses a two-dot diacritic (among others) to represent non-native sounds. The dots are slightly larger than those used for diaeresis or umlaut.

====Diacritic underneath====
{{see also|Romanization}}
The IPA specifies a "subscript umlaut", for example Hindi {{IPA|[kʊm̤ar]}} "potter";<ref name="IPA below" />{{rp|25}} the [[ALA-LC romanization]] system provides for its use and is one of the [[Romanization of Persian#Main romanization schemes|main schemes to romanize Persian]] (for example, rendering {{angbr|{{lang|fa|ض}}}} as {{angbr|z̤}}). The notation was used to write some Asian languages in Latin script, for example [[Red Karen language|Red Karen]].

The double-dot underneath a vowel is still used in [[Bàng-uâ-cê|Fuzhou romanization]] of [[Eastern Min]] to indicate a modified vowel sound; placing the modifier diacritic underneath the vowel letter makes it easier to combine it with tonal diacritics above the letter, as in the word Mìng-dĕ̤ng-ngṳ̄ ("Eastern Min language").

====Side dots====
The diacritics ''' 〮''' and '''〯'''&nbsp;, known as Bangjeom ({{lang|ko|방점; 傍點}}), were used to mark pitch accents in [[Hangul]] for [[Middle Korean]]. They were written to the left of a syllable in vertical writing and above a syllable in horizontal writing.

==Computer encodings==
===In Unicode <span class="anchor" id="Combining diaeresis"></span> ===
[[Character encoding]] generally treats the umlaut and the diaeresis as the same diacritic mark. [[Unicode]] refers to both as diaereses without making any distinction, although the term itself [[:wikt:diaeresis|has a more precise literary meaning]]. For example, {{unichar|00F6|LATIN SMALL LETTER O WITH DIAERESIS}} represents both ''o-umlaut'' and ''o-diaeresis'', while similar codes are used to represent all such cases.

Unicode encodes a number of cases of "letter with a two dots diacritic" as [[precomposed character]]s and these are displayed below. (Unicode uses the term "Diaeresis" for all two-dot diacritics, irrespective of the actual term used for the language in question.) In addition, many more symbols may be composed using the [[combining character]] facility, {{unichar|0308|Combining diaeresis|cwith=◌|nlink=combining character}}, that may be used with any letter or other diacritic to create a customised symbol but this does not mean that the result has any real-world application and are not shown in the table. <!-- AND PLEASE DO NOT TRY TO ADD THEM -->
{{Letters with diacritic/header}}<!--
-->{{hlist|{{Letters with diacritic/diacritic|format=char|d=diaeresis}}<!--
-->{{Letters with diacritic/scriptname|1=Latin}}[[Ä|Ä{{NNBSP}}ä]]
| [[Ä|Ǟ{{NNBSP}}ǟ]]
| [[C̈|C̈{{NNBSP}}c̈]]
| [[Ë|Ë{{NNBSP}}ë]]
| [[Ï|Ï{{NNBSP}}ï]]
| [[Í|Ḯ{{NNBSP}}ḯ]]
| [[J̈|J̈{{NNBSP}}j̈]]
| K̈{{NNBSP}}k̈
| L̈{{NNBSP}}l̈
| M̈{{NNBSP}}m̈
| [[N-diaeresis|N̈{{NNBSP}}n̈]]
| [[Ö|Ö{{NNBSP}}ö]]
| [[Livonian language|Ȫ{{NNBSP}}ȫ]]
| [[Ogonek|Ǫ̈{{NNBSP}}ǫ]]̈
| [[Ö|Ṏ{{NNBSP}}ṏ]]
| [[S̈|S̈{{NNBSP}}s̈]]
| [[T-diaeresis|T̈{{NNBSP}}ẗ]]
| [[Ü|Ü{{NNBSP}}ü]]
| [[Ü|Ǖ{{NNBSP}}ǖ]]
| [[Ü|Ǘ{{NNBSP}}ǘ]]
| [[Ü|Ǚ{{NNBSP}}ǚ]]
| [[Ü|Ǜ{{NNBSP}}ǜ]]
| Ṳ{{NNBSP}}ṳ
| [[Ü|Ṻ{{NNBSP}}ṻ]]
| [[Uralic Phonetic Alphabet|ᴞ]]
<!--
-->{{Letters with diacritic/scriptname|1=Greek}}[[Greek diacritics|Ϊ{{NNBSP}}ϊ]]
| [[Greek diacritics|ῒ ΐ ῗ]]
| [[Greek diacritics|Ϋ{{NNBSP}}ϋ]]
| [[Greek diacritics|ῢ ΰ ῧ]]
| [[Upsilon|ϔ]]<!-- 
-->{{Letters with diacritic/scriptname|1=Cyrillic}}[[A with diaeresis (Cyrillic)|Ӓ{{NNBSP}}ӓ]]
| [[Yo (Cyrillic)|Ё{{NNBSP}}ё]]
| [[Schwa with diaeresis|Ӛ{{NNBSP}}ӛ]]
| [[Zhe with diaeresis|Ӝ{{NNBSP}}ӝ]]
| [[Ze with diaeresis|Ӟ{{NNBSP}}ӟ]]
| [[I with diaeresis (Cyrillic)|Ӥ{{NNBSP}}ӥ]]
| [[Yi (Cyrillic)|Ї{{NNBSP}}ї]]
| [[O with diaeresis (Cyrillic)|Ӧ{{NNBSP}}ӧ]]
| [[Oe with diaeresis|Ӫ{{NNBSP}}ӫ]]
| [[U with diaeresis (Cyrillic)|Ӱ{{NNBSP}}ӱ]]
| [[Che with diaeresis|Ӵ{{NNBSP}}ӵ]]
| [[Yerý with diaeresis|Ӹ{{NNBSP}}ӹ]]
| [[E with diaeresis (Cyrillic)|Ӭ{{NNBSP}}ӭ]]
}}{{Letters with diacritic/footer}}<!--

-->

Both the combining character {{tt|U+0308}} and the pre-composed codepoints may be regarded as an umlaut or a diaeresis according to context. Compound diacritics are possible, for example {{unichar|01DA|LATIN SMALL LETTER U WITH DIAERESIS AND CARON}}, used as a [[Ü#Tonal marks for Hanyu Pinyin|tonal marks for Hanyu Pinyin]], which uses both a two dots diacritic with a [[caron]] diacritic. Conversely, when the letter to be accented is an {{angbr|i}}, the diacritic replaces the [[tittle]], thus: {{angbr|ï}}.

Sometimes, there's a need to distinguish between the umlaut sign and the diaeresis sign. For instance, either may [[German orthography#Umlaut diacritic usage|appear in a German name]]. ISO/IEC JTC 1/SC 2/WG 2 recommends the following for these cases:<ref>{{cite web |title=Every character has a story #24: U+0308 (COMBINING DIAERESIS) |first=Michael S |last=Kaplan | date=4 September 2006 |url=http://archives.miloush.net/michkap/archive/2006/09/04/738263.html}}</ref>
* To represent the '''umlaut''' use the Combining Diaeresis (U+0308)
* To represent the '''diaeresis''' use [[Combining Grapheme Joiner]] (CGJ, U+034F) + Combining Diaeresis (U+0308)
The same advice can be found in the official Unicode FAQ.<ref>{{cite web |title=Characters and Combining Marks {{!}} Q: Unicode doesn't seem to distinguish between tréma and umlaut, but I need to distinguish. What shall I do? |url=https://unicode.org/faq/char_combmark.html#18 |publisher=Unicode Consortium}}</ref>

Since version 3.2.0, Unicode also provides {{unichar|0364|COMBINING LATIN SMALL LETTER E|cwith=◌}} which can produce the older umlaut typography.

Unicode provides a combining double dot below as {{unichar|0324|Combining diaeresis below|cwith=◌}}.

Finally, for use with the [[N'Ko script]], there is {{unichar|07F3|NKO combining double dot above|cwith=◌}}.

===Pre-Unicode===
{{broader|Western Latin character sets (computing)}}
[[ASCII]], a seven-bit code with just 95 "printable" characters, has no provision for any kind of dot diacritic. Subsequent standardisation treated ASCII as the US national variant of [[ISO/IEC 646]]: the French, German and other national variants [[ISO/IEC 646#Variant comparison chart|reassigned a few code points]] to specific vowels with diacritics, as precomposed characters. Some of these variants also defined the sequence {{tt|e}},backspace,{{tt|"}} as producing {{tt|ë}} but few terminals supported this.
	
The subsequent (eight bit) [[ISO 8859-1]] character encoding includes the letters ''ä'', ''ë'', ''ï'', ''ö'', ''ü'', and their respective [[majuscule|capital]] forms, as well as ''ÿ'' in [[lower case]] only, with ''Ÿ'' added in the revised edition [[ISO 8859-15]] and [[Windows-1252]].

==Computer usage <span class="anchor" id="Computer usage"></span> <span class="anchor" id="Letters with diacritic"></span> <span class="anchor" id="Letters with the two-dot diacritic"></span>==
[[File:Tastatur-Umlaute-deutsch.jpg|thumb|right|Letters with umlaut on a [[German keyboard|German computer keyboard]].]]
[[Character encoding]] generally treats the umlaut and the diaeresis as the same diacritic mark. [[Unicode]] refers to both as diaereses without making any distinction, although the term itself [[:wikt:diaeresis|has a more precise literary meaning]]. For example, {{unichar|00F6|LATIN SMALL LETTER O WITH DIAERESIS}} represents both ''o-umlaut'' and ''o-diaeresis'', while similar codes are used to represent all such cases.

In countries where the local language(s) routinely include letters with diacritics, local keyboards are typically engraved with those symbols.
If letters with double dots are not present on the keyboard, there are a number of ways to input them into a computer system. (For details, see local sources, computer system documentation and the article [[Unicode input]].)  <!-- Per [[WP:NOTHOWTO]], it is not the function of Wikipedia to tell people how to do things. -->

==See also==
* [[Dot (diacritic)]]
* [[Two dots (disambiguation)]]
* [[English terms with diacritical marks]]

==Notes==
{{notelist}}

==References==
{{Reflist}}

==External links==
{{Wiktionary|ä|Ë|ë|ö}}

{{Navbox diacritical marks}}
{{Latin script||diaeresis}}

[[Category:Latin-script diacritics]]
[[Category:Greek-script diacritics]]
[[Category:Cyrillic-script diacritics]]