Triphthong

In phonetics, a triphthong (/ˈtrɪfθɒŋ/ or /ˈtrɪpθɒŋ/) (from Greek τρίφθογγος, "triphthongos", literally "with three sounds," or "with three tones") is a monosyllabic vowel combination involving a quick but smooth movement of the articulator from one vowel quality to another that passes over a third. While "pure" vowels, or monophthongs, are said to have one target articulator position, diphthongs have two, triphthongs three, and tetraphthongs four.

Examples

English

In British Received Pronunciation, monosyllabic triphthongs with R are optionally distinguished from sequences with disyllabic realizations:

[aʊ̯ə̯] as in hour (compare with disyllabic "shower" [aʊ̯.ə])
[aɪ̯ə̯] as in fire (compare with disyllabic "higher" [aɪ̯.ə])
[ɔɪ̯ə̯] as in "loir" (compare with final disyllabic sequence in "employer" [ɔɪ̯.ə])

As [eɪ̯] and [əʊ̯] become [ɛə̯] and [ɔː] respectively before /r/, all instances of [eɪ̯.ə] and [əʊ̯.ə] are words with the suffix "-er".

In Cockney, triphthongal realizations [ɪi̯ɐ̯, ɛi̯ə̯, ɔu̯ə̯, æi̯ə̯] of /iə, eə, ɔə, æʊ/ are possible and regarded as "very strongly Cockney".[1] Among these, the triphthongal realization of /ɔə/ occurs most commonly.[2] There is not a complete agreement about their distribution: according to Wells (1982), they "occur in sentence-final position",[3] whereas according to Mott (2012), these are "most common in final position".[2]

Danish

Danish has the following thriphthongs:[4]

[ɛɐ̯u̯] as in færge 'ferry'
[iɐ̯u̯] as in hvirvle 'to whirl'
[œ̞ɐ̯u̯] as in Børge, a given name
[uɐ̯u̯] as in spurv 'sparrow'

Bernese German

Bernese German has the following triphthongs:

[iə̯u̯] as in Gieu 'boy'
[yə̯u̯] as in Gfüeu 'feeling'
[uə̯u̯] as in Schueu 'school'
[yə̯i̯] as in Müej 'trouble'

Northern Bavarian

Northern Bavarian has the following triphthongs:[5]

[ɔu̯ɐ̯] as in /hɔu̯ɐ̯/ (MHG hâr) 'hair', or as in /ɔu̯ɐ̯/ (mhd. ôr) 'ear'
[ɛi̯ə̯] as in /mɛi̯ə̯/ (MHG mêr) 'more'
[ou̯ɐ̯] as in /ʃnou̯ɐ̯/ (MHG snuor) 'cord'
[ei̯ə̯] as in /fei̯ə̯/ (MHG vier) 'four', or as in /ʃnei̯ə̯l/ (MHG snüerelîn) 'small cord'

The Northern Bavarian triphthongs have evolved from combinations of former long vowels or diphthongs from the Middle High German (MHG) period and vocalized r.

Second segment is the nucleus

Portuguese:

[u̯ai̯] as in Paraguai 'Paraguay', iguais 'equal, similar, same (plural)', and quaisquer 'any (plural)'
[u̯ei̯ ~ u̯ɐi̯] as in enxaguei 'I rinsed' and magoei 'I get/did (emotional) hurt'
[u̯ɐ̃u̯] as in saguão 'crush-room'
[u̯ẽi̯ ~ u̯ɐ̃i̯] as in delinquem 'they break the law' and enxaguem 'they rinse'

Some Portuguese triphthongs appear in places where some speakers can break the first segment to form a hiatus (that is, [i̯] or [u̯] are not equivalent to standard Portuguese semivowels [j] and [w] in this case), and as such they are deemed as non-triphthongs by standard, although many or most speakers produce them as such (and even more frequently when speaking colloquially):

[i̯ei̯ ~ i̯ɐi̯] as in mapeei 'I mapped' and maquiei 'I did make up' or (colloquially) 'I disguised (the reality)'
[i̯ou̯] as in clareou 'cleared (singular third person)', miou 'meowed' (second and third persons singular) and piou 'chirped' (singular second and third persons)

In addition, phonetic diphthongs are formed in most Brazilian Portuguese dialects by the vocalization of /l/ in the syllable coda, as well as by yodization of vowels preceding /s/ and /z/ or their syllable-final pre-consonantal allophones [ʃ] and [ʒ], thus if these consonants precede diphthongs, it is likely that a triphthong will form:

[u̯] for aluvial 'alluvial' ([i̯au̯], manual 'manual' ([u̯au̯]) and Gabriel 'Gabriel' ([i̯ɛu̯])
[i̯] for aloés 'aloe plants' ([u̯ɛi̯]) and águias 'eagles' ([i̯ai̯])

Romanian:

[i̯au̯] as in iau 'I take'
[i̯ei̯] as in iei 'you take' ; also ei (they)
[i̯eu̯] as in eu 'I'
[e̯au̯] as in râdeau 'they were laughing'
[e̯ai̯] as in râdeai 'you (sg) were laughing'
[u̯ai̯] as in Uruguay

Spanish:

[u̯ei̯] as in buey 'ox'
[u̯ai̯] as in Uruguay
[i̯ai̯] as in cambiáis 'you [plural]change'
[i̯ei̯] as in cambiéis 'that you may change'

Vietnamese:

[ɨə̯ɪ̯] as in tươi 'fresh'
[ɨə̯ʊ̯] as in rượu 'alcohol'
[ie̯ʊ̯] as in tiêu 'pepper'
[uə̯ɪ̯] as in nuôi 'to nourish'
[u̯ai̯] as in khoai 'potato'
[u̯iɜ] as in khuya 'late into the night'
[u̯iʊ̯] as in khuỵu 'to fall on one's knees'
[u̯ɛʊ̯] as in ngoẹo 'to turn/twist'

Third segment is the nucleus