In phonetics and phonology, gemination, or consonant lengthening, is an articulation of a consonant for a longer period of time than that of a single instance of the same type of consonant. It is distinct from stress. Gemination literally means "twinning" and comes from the same Latin root as "Gemini".
Consonant length is a distinctive feature in certain languages, such as Arabic, Berber, Maltese, Catalan, Danish, Estonian, Finnish, Classical Hebrew, Hindi, Hungarian, Italian, Japanese, Latin, Malayalam, Marathi, Nepali, Persian, Polish, Punjabi, Tamil, Telugu and Urdu. Other languages, such as the English language, do not have phonemic consonant geminates. Vowel length is distinctive in more languages than consonant length.
Consonant gemination and vowel length are two different phenomena in languages like Arabic, Japanese, Finnish and Estonian; however, in languages like Italian, Norwegian and Swedish, vowel length and consonant length are interdependent. For Norwegian and Swedish, at least, gemination of a consonant requires a short vowel in the syllable before it, while ungeminated consonants produce a long vowel in the syllable before it. A clear example are the Norwegian words "tak", and "takk" ("thanks", pronounced with a short /ɑ/.


Lengthened fricatives, nasals, laterals, approximants and trills are simply prolonged. In lengthened stops, the obstruction of the airway is prolonged, which delays release, and the "hold" is lengthened.
In terms of consonant duration, Berber and Finnish are reported to have a 3 to 1 ratio, compared with around 2 to 1 in Japanese, Italian, and Turkish.


Gemination of consonants is distinctive in some languages and then is subject to various phonological constraints that depend on the language.
In some languages, like Italian, Swedish, Faroese, Icelandic, and Luganda, consonant length and vowel length depend on each other. A short vowel within a stressed syllable almost always precedes a long consonant or a consonant cluster, and a long vowel must be followed by a short consonant. In Classical Arabic, a long vowel was lengthened even more before permanently-geminate consonants.
In other languages, such as Finnish, consonant length and vowel length are independent of each other. In Finnish, both are phonemic; taka "back", takka "fireplace" and taakka "burden" are different, unrelated words. Finnish consonant length is also affected by consonant gradation. Another important phenomenon is sandhi, which produces long consonants at word boundaries when there is an archiphonemic glottal stop > otas se "take it!"
In addition, in some Finnish compound words, if the initial word ends in an e, the initial consonant of the following word is geminated: jätesäkki "trash bag", tervetuloa "welcome". In certain cases, a v after a u is geminated by most people: ruuvi "screw", vauva "baby". In the Tampere dialect, if a word receives gemination of v after u, the u is often deleted, and lauantai "Saturday", for example, receives a medial v, which can in turn lead to deletion of u.
Distinctive consonant length is usually restricted to certain consonants. There are very few languages that have initial consonant length; among them are Pattani Malay, Chuukese, Moroccan Arabic, a few Romance languages such as Sicilian and Neapolitan as well as many High Alemannic German dialects, such as that of Thurgovia. Some African languages, such as Setswana and Luganda, also have initial consonant length: it is very common in Luganda and indicates certain grammatical features. In colloquial Finnish and spoken Italian, long consonants are produced between words because of sandhi.
The difference between singleton and geminate consonants varies within and across languages. Sonorants show more distinct geminate-to-singleton ratios while sibilants have less distinct ratios. The bilabial and alveolar geminates are generally longer than velar ones.
The reverse of gemination reduces a long consonant to a short one, which is called degemination. It is a pattern in Baltic-Finnic consonant gradation that the strong grade form of the word is degeminated into a weak grade form of the word: taakka > taakan. As a historical restructuring at the phonemic level, word-internal long consonants degeminated in Western Romance languages: e.g. Spanish /ˈboka/ 'mouth' vs. Italian /ˈbokka/, which continue Latin geminate /kk/.


Afroasiatic languages


Written Arabic indicates gemination with a diacritic shaped like a lowercase Greek omega or a rounded Latin w, called the شَدَّة shadda: ّ . Written above the consonant that is to be doubled, the shadda is often used to disambiguate words that differ only in the doubling of a consonant where the word intended is not clear from the context. For example, in Arabic, Form I verbs and Form II verbs differ only in the doubling of the middle consonant of the triliteral root in the latter form, e. g., درس darasa is a Form I verb meaning to study, whereas درّس darrasa is the corresponding Form II verb, with the middle r consonant doubled, meaning to teach.


In Berber, each consonant has a geminate counterpart, and gemination is lexically contrastive. The distinction between single and geminate consonants is attested in medial position as well as in absolute initial and final positions.
In addition to lexical geminates, Berber also has phonologically-derived and morphologically-derived geminates. Phonologically-derived geminates can surface by concatenation or by complete assimilation. The morphological alternations include imperfective gemination, with some Berber verbs forming their
imperfective stem by geminating one consonant in their perfective stem, as well as quantity alternations between singular and plural forms.

Austronesian languages

in the Philippines, Micronesia, and Sulawesi are known to have geminate consonants.


The Formosan language Kavalan makes use of gemination to mark intensity, as in sukaw "bad" vs. sukkaw "very bad".


The Polynesian language Tuvaluan allows for word-initial geminates, such as mmala "overcooked".

Indo-European languages


In Catalan, geminates are expressed in writing with consonant repetition or the groups tn, tm, tl and tll, such as innecessari 'unnecessary', which is pronounced or ètnic setmana, atleta, rotllo etc. in careful speech. Gemination is not represented if it is purely phonetic, such as the assimilation occurring in tot bé 'all good'. Since the repetition of the letter l generates the digraph ll, which represents the phoneme, the geminate is represented as two ls separated by a punt volat or centered dot :
has a three-way consonant length distinction. For instance:
The word bundene can phonemically be analyzed as, with the middle schwa being assimilated to.


In English phonology, consonant length is not distinctive within root words. For instance, baggage is pronounced, not. However, phonetic gemination does occur marginally.
Gemination is found across words and across morphemes when the last consonant in a given word and the first consonant in the following word are the same fricative, nasal, or stop.
For instance:
With affricates, however, this does not occur. For instance:
In most instances, the absence of this doubling does not affect the meaning, though it may confuse the listener momentarily. The following minimal pairs represent examples where the doubling does affect the meaning in most accents:
In some dialects gemination is also found for some words when the suffix -ly follows a root ending in -l or -ll, as in:
but not
In some varieties of Welsh English, the process takes place indiscriminately between vowels, e.g. in money but it also applies with graphemic duplication, e.g. butter


In French, consonant length is usually not distinctive, but in certain exceptional cases it can be, such as the pair courons vs courrons. Gemination also occurs in case of schwa elision.


In Ancient Greek, consonant length was distinctive, e.g., μέλω "I am of interest" vs. μέλλω "I am going to". The distinction has been lost in the standard and most other varieties, with the exception of Cypriot, some varieties of the southeastern Aegean, and Italy.


Gemination is common in Hindi and Urdu. It is found in words of both Indic and Arabic origin, but not in those of Persian origin:
For aspirated consonants, the geminate is formed by combining the corresponding non-aspirated consonant followed by its aspirated counterpart. There are few examples where an aspirated consonant is truly doubled.
In Standard Italian, consonant strengthening is usually written with two consonants and it is distinctive. For example, bevve, meaning "he/she drank", is phonemically and pronounced, while beve is, pronounced. Tonic syllables are bimoraic and are therefore composed of either a long vowel in an open syllable or a short vowel in a closed syllable. In varieties with post-vocalic weakening of some consonants, geminates are not affected.
Double or long consonants occur not only within words but also at word boundaries, and they are then pronounced but not necessarily written: chi + sa = chissà and vado a casa . All consonants except can be geminated. This word-initial gemination is triggered either lexically by the item preceding the lengthening consonant, or by any word-final stressed vowel.


makes use of gemination to mark intensity, as in gelek "many" vs. gellek "very many" or tijî "full" vs. tijjî "cram full, completely full".


In Latin, consonant length was distinctive, as in anus "old woman" vs. annus "year". Vowel length was also distinctive in Latin, but was not reflected in the orthography. Geminates inherited from Latin still exist in Italian, in which anno and ano contrast with regard to and as in Latin. It has been almost completely lost in French and completely in Romanian. In West Iberian languages, former Latin geminate consonants often evolved to new phonemes, including some instances of nasal vowels in Portuguese and Old Galician as well as most cases of and in Spanish, but phonetic length of both consonants and vowels is no longer distinctive.


In Marathi, the compounding occurs quite frequently, as in the words haṭṭa, kaṭṭā or sattā. It seems to happen most commonly with the dental and retroflex consonants.


In Nepali, all consonants have geminate counterparts except for voiced glottal fricative and approximants. Geminates occur only medially. Examples:
In Norwegian, gemination is indicated in writing by double consonants. Gemination often differentiates between unrelated words. As in Italian, Norwegian uses short vowels before doubled consonants and long vowels before single consonants. There are qualitative differences between short and long vowels:
In Polish, consonant length is indicated with two identical letters. Examples:
Consonant length is distinctive and sometimes is necessary to distinguish words:
Double consonants are common on morpheme borders where the initial or final sound of the suffix is the same as the final or initial sound of the stem. Examples:
in its official script Gurmukhi uses a diacritic called an áddak which is written above the word and indicates that the following consonant is geminate. Gemination is specially characteristic of Punjabi compared to other Indo-Aryan languages like Hindi-Urdu, where instead of the presence of consonant lengthening, the preceding vowel tends to be lengthened. Consonant length is distinctive in Punjabi, for example:
In Russian, consonant length may occur in several situations.
Minimal pairs exist, such as 'to hold' vs 'to support', and their conjugations, or 'length' vs 'long' adj. f.
In Spanish there are geminated consonants in Caribbean Spanish when /l/ and /ɾ/ in syllabic coda are assimilated to the following consonant. Examples of Cuban Spanish:


In Ukrainian, geminates are found between vowels: багаття "bonfire", подружжя "married couple", обличчя "face". Geminates also occur at the start of a few words: лляний "flaxen", forms of the verb лити "to pour", ссати "to suck" and derivatives. Gemination is in some cases semantically crucial; for example, манна means "manna" or "semolina" while мана means "delusion".


is unusual in that gemination can occur word-initially, as well as word-medially. For example, kkapa 'cat', jjajja 'grandfather' and nnyabo 'madam' all begin with geminate consonants.
There are three consonants that cannot be geminated:, and. Whenever morphological rules would geminate these consonants, and are prefixed with, and changes to. For example:
In Japanese, consonant length is distinctive. Gemination in the syllabary is represented with the sokuon, a small tsu: っ for hiragana in native words and ッ for katakana in foreign words. For example, 来た means "came; arrived", while 切った means "cut; sliced". With the influx of gairaigo into Modern Japanese, voiced consonants have become able to geminate as well: バグ means " bug", and バッグ means "bag". Distinction between voiceless gemination and voiced gemination is visible in pairs of words such as キット and キッド. In addition, in some variants of colloquial Modern Japanese, gemination may be applied to some adjectives and adverbs in order to add emphasis: すごい contrasts with すっごい ; 思い切り contrasts with 思いっ切り.


In Korean, geminates arise from assimilation, and they are distinctive.


In Turkish, gemination in word stem is exclusive to loanwords. Gemination is indicated by two identical letters as in most languages that have phonemic gemination.
Loanwords originally ending with a phonemic geminated consonant are always written and pronounced without the ending gemination as in Arabic.
Although gemination is resurrected when the word takes a suffix.
Gemination also occurs when a suffix starting with a consonant comes after a word that ends with the same consonant.
In Malayalam, compounding is phonologically conditioned so gemination occurs at words' internal boundaries.
Consider following example:


has three phonemic lengths; however, the third length is a suprasegmental feature, which is as much tonal patterning as a length distinction. It is traceable to allophony caused by now-deleted suffixes, for example half-long linna < *linnan "of the city" vs. overlong linna < *linnahan "to the city".


Consonant length is phonemic in Finnish, for example takka and taka . Consonant gemination occurs with simple consonants and between syllables in the pattern -vowel-sonorant-stop-stop-vowel but not generally in codas or with longer syllables. Sandhi often produces geminates.
Both consonant and vowel gemination are phonemic, and both occur independently, e.g. Mali, maali, malli, maallinen.
In Standard Finnish, consonant gemination of exists only in interjections, new loan words and in the playful word "", with its origins in the 19th century, and derivatives of that word.
In many Finnish dialects there are also the following types of special gemination in connection with long vowels: the southwestern special gemination, with lengthening of stops + shortening of long vowel, of the type leipää< leippä; the common gemination, with lengthening of all consonants in short, stressed syllables, of the type putoaa > puttoo and its extension ; the eastern dialectal special gemination, which is the same as the common gemination but also applies to unstressed syllables and certain clusters, of the types lehmiä > lehmmii and maksetaan > maksettaan.


In Hungarian, consonant length is phonemic, e.g. megy, 'goes' and meggy, 'sour cherry'.

Sami languages

Most Sami languages contrast three different degrees of consonant length. These often contrast in different forms within a single inflectional paradigm, as in Northern Sami goarˈrut "let's sew!" versus goarrut "to sew, we sew" versus goarut "you sew". Often, progressively longer consonants correspond to a progressively shorter preceding vowel.
In Proto-Samic, the common ancestor of the Sami languages, there was already a contrast between single and geminate consonants, inherited from Proto-Uralic. A process called consonant gradation then lengthened all consonants when they stood at the end of a stressed syllable, if the next syllable was open. The subsequent loss of final consonants and vowels in the later Sami languages made this process contrastive, resulting in as many as four contrastive lengths. The modern Sami languages have reduced this to three, by merging the unlengthened geminates with the lengthened single consonants.


In Wagiman, an indigenous Australian language, consonant length in stops is the primary phonetic feature that differentiates fortis and lenis stops. Wagiman does not have phonetic voice. Word-initial and word-final stops never contrast for length.


In written language, consonant length is often indicated by writing a consonant twice, but can also be indicated with a special symbol, such as the shadda in Arabic, the dagesh in Classical Hebrew, or the sokuon in Japanese.
In the International Phonetic Alphabet, long consonants are normally written using the triangular colon , e.g. penne , though doubled letters are also used.
Doubled orthographic consonants do not always indicate a long phonetic consonant.