In phonetics, a triphthong (UK: /ˈtrɪfθɒŋ,ˈtrɪpθɒŋ/TRIF-thong, TRIP-thong, US: /-θɔːŋ/-thawng) (from Greekτρίφθογγοςtriphthongos, lit.'with three sounds' or 'with three tones') is a monosyllabicvowel 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 and triphthongs three.
Triphthongs are not to be confused with disyllabic sequences of a diphthong followed by a monophthong, as in German Feuer[ˈfɔʏ.ɐ] 'fire', where the final vowel is longer than those found in triphthongs.
Examples
Triphthongs that feature close elements typically analyzed as /j/ and /w/ in phonology are not listed. For instance, the Polish word łój[wuj] 'tallow' is typically analyzed as /CVC/ - a sequence of a consonant followed by a vowel and another consonant. This is because the palatal approximant is resyllabified in some inflected forms, such as łojami[wɔˈjami] (instr. pl.), and also because /w/ occurs word-finally after a consonant just like /l/ does (compare przemysł[ˈpʂɛmɨsw] 'industry' with Przemyśl[ˈpʂɛmɨɕl] 'Przemyśl'), which means that both of them behave more like consonants than vowels.
On the other hand, [ɪ̯,i̯,ʊ̯,u̯] are not treated as phonetic consonants when they arise from vocalization of /l/, /v/ or /ɡ/ as they do not share almost all of their features with those three.
They have arisen due to the vocalization of /l/ in the syllable coda; compare the last two with Standard German Gefühl[ɡəˈfyːl] and Schule[ˈʃuːlə], the last one with a schwa not present in the Bernese word.
In British Received Pronunciation, and most other non-rhotic (r-dropping) varieties of English, monosyllabic triphthongs with R are optionally distinguished from sequences with disyllabic realizations:
[aʊ̯ə̯] as in: flour (compare with disyllabic "flower" [aʊ̯.ə])
[aɪ̯ə̯] as in: byre (compare with disyllabic "buyer" [aɪ̯.ə])
[ɔɪ̯ə̯] as in: coir (compare with disyllabic "coyer" [ɔɪ̯.ə]), loir (compare with disyllabic "lawyer" [ɔɪ̯.ə])
As [eɪ̯] and [əʊ̯] become [ɛə̯] and [ɔː] respectively before /r/, most instances of [eɪ̯.ə] and [əʊ̯.ə] are words with the suffix "-er", such as player and lower. Other instances are loanwords, such as boa.
[aʊ̯ə̯,aɪ̯ə̯,ɔɪ̯ə̯] are sometimes written as ⟨awə,ajə,ɔjə⟩, or similarly.[citation needed]
[i̯ai̯] as in cambiáis[kamˈbi̯ai̯s] 'you [informal plural] change'
[i̯ei̯] as in cambiéis[kamˈbi̯ei̯s] 'that you [informal plural] may change'
The last two are mostly restricted to European Spanish. In Latin American Spanish (which has no distinct vosotros form), the corresponding words are cambian[ˈkambi̯an] and cambien[ˈkambi̯en], with a rising-opening diphthong followed by a nasal stop and initial, rather than final stress. In phonology, [u̯ei̯,u̯ai̯,i̯ai̯,i̯ei̯] are analyzed as a monosyllabic sequence of three vowels: /uei,uai,iai,iei/. In Help:IPA/Spanish, those triphthongs are transcribed ⟨wej,waj,jaj,jej⟩: [ˈbwej], [uɾuˈɣwaj], [kamˈbjajs], [kamˈbjejs]
