[4][5] In terms of consonant duration, Berber and Finnish are reported to have a 3-to-1 ratio,[6] compared with around 2-to-1 (or lower) in Japanese,[7] Italian, and Turkish.
Another important phenomenon is sandhi, which produces long consonants at word boundaries when there is an archiphonemic glottal stop |otaʔ se| > otas se 'take it (imperative)!'.
In colloquial Finnish and Italian, long consonants occur in specific instances as sandhi phenomena.
It is a pattern in Baltic-Finnic consonant gradation that the strong grade (often the nominative) form of the word is degeminated into a weak grade (often all the other cases) form of the word: taakka > taakan (burden, of the burden).
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/, both of which evolved from Latin /ˈbukka/.
[8] Written Arabic indicates gemination with a diacritic (ḥaraka) shaped like a lowercase Greek omega or a rounded Latin w, called the شَدَّة shadda: ّ .
[9] The Formosan language Kavalan makes use of gemination to mark intensity, as in sukaw 'bad' vs. sukkaw 'very bad'.
The following minimal pairs represent examples where the doubling does affect the meaning in most accents: Note that whenever [(ɹ)] appears (in brackets), non-rhotic dialects of English don't have the gemination, but rather lengthen the preceding vowel.
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 [ˈmɜn.niː] but it also applies with graphemic duplication (thus, orthographically dictated), e.g. butter [ˈbɜt̚.tə][14] In French, gemination is usually not phonologically relevant and therefore does not allow words to be distinguished: it mostly corresponds to an accent of insistence (c'est terrifiant realised [ˈtɛʁ.ʁi.fjɑ̃]), or meets hyper-correction criteria: one "corrects" one's pronunciation, despite the usual phonology, to be closer to a realization that one imagines to be more correct: thus, the word illusion is sometimes pronounced [il.lyˈzjɔ̃] by influence of the spelling.
In Ancient Greek, consonant length was distinctive, e.g., μέλω [mélɔː] 'I am of interest' vs. μέλλω [mélːɔː] 'I am going to'.
In Urdu, gemination is represented by the Shadda diacritic, which is usually omitted from writings, and mainly written to clear ambiguity.
This word-initial gemination is triggered either lexically by the item preceding the lengthening consonant (e.g. by preposition a 'to, at' in [a kˈkaːsa] a casa 'homeward' but not by definite article la in [la ˈkaːsa] la casa 'the house'), or by any word-final stressed vowel ([parˈlɔ ffranˈtʃeːze] parlò francese 's/he spoke French' but [ˈparlo franˈtʃeːze] parlo francese 'I speak French').
Vowel length was also distinctive in Latin until about the fourth century, and was reflected in the orthography with an apex.
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 /ɲ/ and /ʎ/ in Spanish, but phonetic length of both consonants and vowels is no longer distinctive.
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 (depending on the position of the suffix), after devoicing.
In contrast, the shadda, which is used to represent gemination in the Shahmukhi script, is not necessarily written, retaining the tradition of the original Arabic script and Persian language, where diacritics are usually omitted from writing, except to clear ambiguity, and is written above the geminated consonant.
Minimal pairs (or chronemes) exist, such as подержать [pədʲɪrˈʐatʲ] 'to hold' vs поддержать [pədʲːɪrˈʐatʲ] 'to support', and their conjugations, or длина [dlʲɪˈna] 'length' vs длинна [dlʲɪˈnːa] 'long' adj.
[19] Examples of Cuban Spanish: Luganda (a Bantu language) is unusual in that gemination can occur word-initially, as well as word-medially.
In addition, in some variants of colloquial Modern Japanese, gemination may be applied to some adjectives and adverbs (regardless of voicing) in order to add emphasis: すごい (sugoi, 'amazing') contrasts with すっごい (suggoi, 'really amazing'); 思い切り (おもいきり, omoikiri, 'with all one's strength') contrasts with 思いっ切り (おもいっきり, omoikkiri, 'really with all one's strength').
In Malayalam, compounding is phonologically conditioned[23] called as sandhi and gemination occurs at word boundaries.
Consider following example: Gemination also occurs in a single morpheme like കള്ളം (kaḷḷaṁ) which has a different meaning from കളം (kaḷaṁ).
Both consonant and vowel gemination are phonemic, and both occur independently, e.g. Mali, maali, malli, maallinen (Karelian surname, 'paint', 'model', and 'secular').
In many Finnish dialects there are also the following types of special gemination in connection with long vowels: the southwestern special gemination (lounaismurteiden erikoisgeminaatio), with lengthening of stops + shortening of long vowel, of the type leipää < leippä; the common gemination (yleisgeminaatio), with lengthening of all consonants in short, stressed syllables, of the type putoaa > puttoo and its extension (which is strongest in the northwestern Savonian dialects); the eastern dialectal special gemination (itämurteiden erikoisgeminaatio), 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 written language, consonant length is often indicated by writing a consonant twice (ss, kk, pp, and so forth), 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 ː, e.g. penne [penːe] ('feathers', 'pens', also a kind of pasta), though doubled letters are also used (especially for underlying phonemic forms, or in tone languages to facilitate diacritic marking).