Diphthong

A diphthong ( /ˈdɪfθɒŋ/ or /ˈdɪpθɒŋ/;^[1] Greek: δίφθογγος, diphthongos, literally "two sounds" or "two tones"), also known as a gliding vowel, refers to two adjacent vowel sounds occurring within the same syllable. Technically, a diphthong is a vowel with two different targets: That is, the tongue moves during the pronunciation of the vowel. In most dialects of English, the words eye, hay, boy, low, and cow contain diphthongs.

Diphthongs contrast with monophthongs, where the tongue doesn't move and only one vowel sound is heard in a syllable. Where two adjacent vowel sounds occur in different syllables—for example, in the English word re-elect—the result is described as hiatus, not as a diphthong.

Diphthongs often form when separate vowels are run together in rapid speech during a conversation. However, there are also unitary diphthongs, as in the English examples above, which are heard by listeners as single-vowel sounds (phonemes).^[2]

International Phonetic Alphabet

In the International Phonetic Alphabet, pure vowels are transcribed with one letter, as in English sun [sʌn]. Diphthongs are transcribed with two letters, as in English sign [saɪ̯n] or sane [seɪ̯n]. The two vowel symbols are chosen to represent the beginning and ending positions of the tongue, though this can be only approximate.

The non-syllabic diacritic (an inverted breve below, ⟨◌ ̯⟩) can be placed under the less prominent component to show that it is part of a diphthong rather than a separate vowel. It is, however, usually omitted in languages such as English, where there is not likely to be any confusion.

Without the diacritic, the sequence [ai] can represent either a diphthong ([ai̯]) or two vowels in hiatus ([a.i]).

Types

Falling and rising

Falling (or descending) diphthongs start with a vowel quality of higher prominence (higher pitch or volume) and end in a semivowel with less prominence, like [aɪ̯] in eye, while rising (or ascending) diphthongs begin with a less prominent semivowel and end with a more prominent full vowel, similar to the [ja] in yard. (Note that "falling" and "rising" in this context do not refer to vowel height; the terms "opening" and "closing" are used instead. See below.) The less prominent component in the diphthong may also be transcribed as an approximant, thus [aj] in eye and [ja] in yard. However, when the diphthong is analysed as a single phoneme, both elements are often transcribed with vowel letters (/aɪ̯/, /ɪ̯a/). Note also that semivowels and approximants are not equivalent in all treatments, and in the English and Italian languages, among others, many phoneticians do not consider rising combinations to be diphthongs, but rather sequences of approximant and vowel. There are many languages (such as Romanian) that contrast one or more rising diphthongs with similar sequences of a glide and a vowel in their phonetic inventory^[3] (see semivowel for examples).

Closing, opening, and centering

In closing diphthongs, the second element is more close than the first (e.g. [ai]); in opening diphthongs, the second element is more open (e.g. [ia]). Closing diphthongs tend to be falling ([ai̯]), and opening diphthongs are generally rising ([i̯a]), as open vowels are more sonorous and therefore tend to be more prominent. However, exceptions to this rule are not rare in the world's languages. In Finnish, for instance, the opening diphthongs /ie̯/ and /uo̯/ are true falling diphthongs, since they begin louder and with higher pitch and fall in prominence during the diphthong.

A third, rare type of diphthong that is neither opening nor closing is height-harmonic diphthongs, with both elements at the same vowel height.^{[citation needed]} These were particularly characteristic of Old English, which had diphthongs such as /æɑ̯/, /eo̯/.

A centering diphthong is one that begins with a more peripheral vowel and ends with a more central one, such as [ɪə̯], [ɛə̯], and [ʊə̯] in Received Pronunciation or [iə̯] and [uə̯] in Irish. Many centering diphthongs are also opening diphthongs ([iə̯], [uə̯]).

diphthongs may contrast in how far they open or close. For example, Samoan contrasts low-to-mid with low-to-high diphthongs:

• ’ai [ʔai̯] 'probably'
• ’ae [ʔae̯] 'but'
• ’auro [ʔau̯ɾo] 'gold'
• ao [ao̯] 'a cloud'

Length

Languages differ in the length of diphthongs, measured in terms of morae. In languages with phonemically short and long vowels, diphthongs typically behave like long vowels, and are pronounced with a similar length.^{[citation needed]} In languages with only one phonemic length for pure vowels, however, diphthongs may be behave like pure vowels.^{[citation needed]} For example, in Icelandic, both monophthongs and diphthongs are pronounced long before single consonants and short before most consonant clusters.

Some languages contrast short and long diphthongs. In some languages, such as Old English, these behave like short and long vowels, occupying one and two morae, respectively. In other languages, however, such as Ancient Greek, they occupy two and three morae, respectively, with the first element rather than the diphthong as a whole behaving as a short or long vowel.^{[citation needed]} Languages that contrast three quantities in diphthongs are extremely rare, but not unheard of; Northern Sami is known to contrast long, short and "finally stressed" diphthongs, the last of which are distinguished by a long second element.^{[citation needed]}

Difference between a vowel and semivowel

While there are a number of similarities, diphthongs are not the same as a combination of a vowel and an approximant or glide. Most importantly, diphthongs are fully contained in the syllable nucleus^[4][5] while a semivowel or glide is restricted to the syllable boundaries (either the onset or the coda). This often manifests itself phonetically by a greater degree of constriction.^[6] though this phonetic distinction is not always clear.^[7] The English word yes, for example, consists of a palatal glide followed by a monophthong rather than a rising diphthong. In addition, while the segmental elements must be different in diphthongs so that [ii̯], when it occurs in a language, does not contrast with [iː] though it is possible to contrast [ij] and [iː].^[8]

Nonetheless, in practice the choice of treating a diphthong or diphthong-like element as a single phoneme, a sequence of two vowels or a combination of a vowel and a glide is based not on the phonetic nature of the diphthong but on systemic properties of the language.^{[citation needed]} The following are examples of systemic characteristics that tend to determine which analysis is chosen:^{[citation needed]}

• The presence of alternations among related words or related dialects between diphthongs and monophthongs, sequences of vowel and consonant, or sequences of two vowels in separate syllables
• The restrictions (or lack thereof) on the diphthongs that can occur
• The existence of glides such as /w/ and /j/ as separate phonemes in the language
• The behavior of the diphthong when a vowel directly follows
• The historical origin of the diphthong

Furthermore, falling diphthongs are more likely to be analyzed as unit phonemes than rising diphthongs.

As an example, the English diphthongs are usually considered single phonemes because they (mostly) originated historically as monophthongs, alternate with monophthongs in pairs such as divine vs. divinity, maintain their coherence when another vowel follows, and other, similar-looking diphthongs like /eu/ do not exist in the language.^{[citation needed]} On the other hand, Japanese /ai/ is normally analyzed as a sequence of two vowels; Spanish /ai/ is normally analyzed as either a sequence of two vowels or of a vowel and a glide, depending on the analysis.^{[citation needed]}

Examples

Germanic languages

English

See also: IPA chart for English dialects

All English diphthongs are falling, apart from /juː/, which can be analyzed as [i̯uː].

In words coming from Middle English, most cases of the Modern English diphthongs [aɪ̯, oʊ̯, eɪ̯, aʊ̯] originated from the Middle English long monophthongs [iː, ɔː, aː, uː] through the Great Vowel Shift, although some cases of [oʊ̯, eɪ̯] originated from the Middle English diphthongs [ɔu̯, aɪ̯]. Since these diphthongs in most cases originated from monophthongs, they are considered single phonemes and not sequences of two phonemes.

Standard English diphthongs

	RP (British)	Australian	American
			GA	Canadian
low	[əʊ̯]	[əʉ̯]	[oʊ̯]
loud	[aʊ̯]	[æɔ̯]	[aʊ̯]	[aʊ̯]
lout				[əʊ̯][t2 1]
lied	[aɪ̯]	[ɑe̯]	[aɪ̯]
light			[əɪ̯][t2 1]
lane	[eɪ̯]	[æɪ̯]	[eɪ̯]
loin	[ɔɪ̯]	[oɪ̯]	[ɔɪ̯]
loon	[uː]	[ʉː]	[ʊu̯][t2 2]
lean	[iː]	[ɪi̯][t2 2]	[ɪi̯][t2 2]
leer	[ɪə̯]	[ɪə̯]	[ɪɚ̯][t2 3]
lair	[ɛə̯][t2 4]	[eː][t2 4]	[ɛɚ̯][t2 3]
lure	[ʊə̯][t2 4]	[ʊə̯]	[ʊɚ̯][t2 3]

1. ^ ^{a b} Canadian English exhibits allophony of /aʊ̯/ and /aɪ̯/ called Canadian raising. GA and RP have raising to a lesser extent in /aɪ̯/.
2. ^ ^{a b c} The erstwhile monophthongs /iː/ and /uː/ are diphthongized in many dialects. In many cases they might be better transcribed as [uu̯] and [ii̯], where the non-syllabic element is understood to be closer than the syllabic element. They are sometimes transcribed /uw/ and /ij/.
3. ^ ^{a b c} In rhotic dialects, words like pair, poor, and peer can be analyzed as diphthongs, although other descriptions analyze them as vowels with [ɹ] in the coda.
4. ^ ^{a b c} In Received Pronunciation, the vowels in lair and lure may be monophthongized to [ɛː] and [oː] respectively (Roach (2004:240)). Australian English speakers more readily monophthongize the former.

Dutch

Diphthongs of Dutch

	Netherlandic[9]	Belgian[10]
zeis	[ɛɪ̯]
ui	[œʏ̯]
zout	[ʌʊ̯]	[ɔʊ̯]
beet[t1 1]	[eɪ̯]	[eː]
neus[t1 1]	[øʏ̯]	[øː]
boot[t1 1]	[oʊ̯]	[oː]

1. ^ ^{a b c} [eɪ̯], [øʏ̯], and [oʊ̯] are normally pronounced as closing diphthongs except before [ɾ] in the same word, in which case they are centering diphthongs: [eə̯], [øə̯], and [oə̯]. In many dialects, they are monophthongized (See Verhoeven & Van Bael (2002) for more information).

The dialect of Hamont (in Limburg) has five centring diphthongs and contrasts long and short forms of [ɛɪ̯], [œʏ̯], [ɔʊ̯], and [ɑʊ̯].^[11]

German

Standard German

Phonemic diphthongs in German:

• /aɪ̯/ as in Ei ‘egg’
• /aʊ̯/ as in Maus ‘mouse’
• /ɔʏ̯/ as in neu ‘new’

In the varieties of German that vocalize the /r/ in the syllable coda, other diphthongal combinations may occur. These are only phonetic diphthongs, not phonemic diphthongs, since the vocalic pronunciation [ɐ̯] alternates with consonantal pronunciations of /r/ if a vowel follows, cf. du hörst [duː ˈhøːɐ̯st] ‘you hear’ – ich höre [ʔɪç ˈhøːʀə] ‘I hear’. These phonetic diphthongs may be as follows:

• [eːɐ̯] as in er ‘he’
• [iːɐ̯] as in ihr ‘you (plural)’
• [oːɐ̯] as in Ohr ‘ear’
• [øːɐ̯] as in Öhr ‘eye (hole in a needle)’
• [uːɐ̯] as in Uhr ‘clock’
• [yːɐ̯] as in Tür ‘door’
• [aːɐ̯] as in wahr ‘true’

Bernese German

The diphthongs of some German dialects differ a lot from standard German diphthongs. The Bernese German diphthongs, for instance, correspond rather to the Middle High German diphthongs than to standard German diphthongs:

• /iə̯/ as in lieb ‘dear’
• /uə̯/ as in guet ‘good’
• /yə̯/ as in müed ‘tired’
• /ei̯/ as in Bei ‘leg’
• /ou̯/ as in Boum ‘tree’
• /øi̯/ as in Böim ‘trees’

Apart from these phonemic diphthongs, Bernese German has numerous phonetic diphthongs due to L-vocalization in the syllable coda, for instance the following ones:

• [au̯] as in Stau ‘stable’
• [aːu̯] as in Staau ‘steel’
• [æu̯] as in Wäut ‘world’
• [æːu̯] as in wääut ‘elects’
• [ʊu̯] as in tschúud ‘guilty’

Yiddish

Yiddish has three diphthongs:^[12]

• [ɛɪ̯] as in [plɛɪ̯tə] פּליטה ('refugee' f.)
• [aɛ̯] as in [naɛ̯n] נײַן ('nine')
• [ɔə̯] as in [ɔəf̯n̩] אופֿן ('way')

Diphthongs may reach a higher target position (towards /i/) in situations of coarticulatory phenomena or when words with such vowels are being emphasized.

Norwegian

There are five diphthongs in Norwegian:

• [æɪ̯] as in nei, "no"
• [øʏ̯] as in øy, "island"
• [æʉ̯] as in sau, "sheep"
• [ɑɪ̯] as in hai, "shark"
• [ɔʏ̯] as in joik, "Sami song"

An additional diphthong, [ʉ̫ʏ̯], occurs only in the word hui in the expression i hui og hast "in great haste". The number and form of diphthongs vary between dialects.

Faroese

Diphthongs in Faroese are:

• /ai/ as in bein (can also be short)
• /au/ as in havn
• /ɛa/ as in har, mær
• /ɛi/ as in hey
• /ɛu/ as in nevnd
• /œu/ as in nøvn
• /ʉu/ as in hús
• /ʊi/ as in mín, bý, ið (can also be short)
• /ɔa/ as in ráð
• /ɔi/ as in hoyra (can also be short)
• /ɔu/ as in sól, ovn

Icelandic

Diphthongs in Icelandic are the following:

• /au̯/ as in átta, "eight"
• /ou̯/ as in nóg, "enough"
• /œy̯/ as in auga, "eye"
• /ai̯/ as in hæ, "hi"
• /ei̯/ as in þeir, "they"

Combinations of semivowel /j/ and a vowel are the following:

• /ja/ as in jata, "manger"
• /jau̯/ as in já, "yes"
• /jo/ as in joð, "iodine," "jay," "yod" (only in a handful of words of foreign origin)
• /jou̯/ as in jól, "Christmas"
• /jœ/ as in jötunn, "giant"
• /jai̯/ as in jæja, "oh well"

Romance languages

French

In French, /wa/, /wɛ̃/, and /ɥi/ may be considered true diphthongs (that is, fully contained in the syllable nucleus: [u̯a], [u̯ɛ̃], [y̯i]). Other sequences are considered part of a glide formation process that turns a high vowel into a semivowel (and part of the syllable onset) when followed by another vowel.^[13]

Diphthongs

• /wa/ [u̯a] as in roi "king"
• /wɛ̃/ [u̯ɛ̃] as in groin "muzzle"
• /ɥi/ [y̯i] as in huit "eight"

Semivowels

• /wi/ as in oui "yes"
• /jɛ̃/ as in lien "bond"
• /jɛ/ as in Ariège
• /aj/ as in travail "work"
• /ɛj/ as in Marseille
• /œj/ as in feuille "leaf"
• /uj/ as in grenouille "frog"
• /jø/ as in vieux "old"

Catalan

Catalan possesses a number of phonetic diphthongs, all of which begin (rising diphthongs) or end (falling diphthongs) in [j] or [w].^[14]

Catalan diphthongs

falling
[aj]	aigua	'water'	[aw]	taula	'table'
[əj]	mainada	'children'	[əw]	caurem	'we will fall'
[ɛj]	remei	'remedy'	[ɛw]	peu	'foot'
[ej]	rei	'king'	[ew]	seu	'his/her'
			[iw]	niu	'nest'
[ɔj]	noi	'boy'	[ɔw]	nou	'new'
			[ow]	jou	'yoke'
[uj]	avui	'today'	[uw]	duu	'he/she is carrying'
rising
[ja]	iaia	'grandma'	[wa]	quatre	'four'
[jɛ]	veiem	'we see'	[wɛ]	seqüència	'sequence'
[je]	seient	'seat'	[we]	ungüent	'ointment'
[jə]	feia	'he/she was doing'	[wə]	qüestió	'question'
			[wi]	pingüí	'penguin'
[jɔ]	iode	'iodine'	[wɔ]	quota	'payment'
[ju]	iogurt	'yoghurt'

In standard Eastern Catalan, rising diphthongs (that is, those starting with [j] or [w]) are only possible in the following contexts:^[15]

• [j] in word initial position, e.g. iogurt.
• Both occur between vowels as in feia and veiem.
• In the sequences [ɡw] or [kw] and vowel, e.g. guant, quota, qüestió, pingüí (these exceptional cases even lead some scholars^[16] to hypothesize the existence of rare labiovelar phonemes /ɡʷ/ and /kʷ/).^[17]

There are also certain instances of compensatory diphthongization in the Majorcan dialect so that /ˈtroncs/ ('logs') (in addition to deleting the palatal plosive) develops a compensating palatal glide and surfaces as [ˈtrojns] (and contrasts with the unpluralized [ˈtronʲc]). Diphthongization compensates for the loss of the palatal stop (part of Catalan's segment loss compensation). There are other cases where diphthongization compensates for the loss of point of articulation features (property loss compensation) as in [ˈaɲ] ('year') vs [ˈajns] ('years').^[18] The dialectal distribution of this compensatory diphthongization is almost entirely dependent on the dorsal plosive (whether it is velar or palatal) and the extent of consonant assimilation (whether or not it is extended to palatals).^[19]

Portuguese

^{[are these diphthongs, or VC?]}

Main article: Portuguese phonology

The Portuguese diphthongs are formed by the labio-velar approximant [w] and palatal approximant [j] with a vowel,^[20] European Portuguese has 14 phonemic diphthongs (10 oral and 4 nasal),^[21] all of which are falling diphthongs formed by a vowel and a nonsyllabic high vowel. Brazilian Portuguese has roughly the same amount, although the two dialects have slightly different pronunciations. A [w] onglide after /k/ or /ɡ/ as in quando [ˈkwɐ̃dʊ] ('when') or guarda [ˈɡwaɾdɐ] ('guard') may also form rising diphthongs and triphthongs. Additionally, in casual speech, adjacent heterosyllabic vowels may combine into diphthongs and triphthongs or even sequences of them.^[22]

Falling diphthongs of Portuguese

oral
	EP[21]	BP		EP	BP
sai	[aj]		mau	[aw]
sei	[ɐj]	[ej]	meu	[ew]
anéis		[ɛj]	véu	[ɛw]
			viu	[iw]
mói	[ɔj]
moita	[oj]		dou	[ow]
anuis	[uj]
nasal
mãe	[ɐ̃j]	[ɐ̃j]	mão	[ɐ̃w]
cem		[ẽj]
anões	[õj]
muita	[ũj]

In addition, phonetic diphthongs are formed in Brazilian Portuguese by the vocalization of /l/ in the syllable coda with words like sol [sɔw] ('sun') and sul [suw] ('south') as well as by yodization of vowels preceding /s/ in words like arroz [aˈʁojs] ('rice') and mas [majs] ('but').^[22]

Spanish

Spanish has six falling diphthongs and eight rising diphthongs. In addition, during fast speech, sequences of vowels in hiatus become diphthongs wherein one becomes non-syllabic (unless they are the same vowel, in which case they fuse together) as in poeta [ˈpo̯eta] ('poet') and maestro [ˈmae̯stɾo] ('teacher'). The Spanish diphthongs are:^[23]

Spanish diphthongs

falling
[ai̯]	aire	'air'	[au̯]	pausa	'pause'
[ei̯]	rey	'king'	[eu̯]	neutro	'neutral'
[oi̯]	hoy	'today'	[ou̯]	bou	'seine fishing'
rising
[ja]	hacia	'towards'	[wa]	cuadro	'picture'
[je]	tierra	'earth'	[we]	fuego	'fire'
			[wi]	fuimos	'we went'
[jo]	radio	'radio'	[wo]	cuota	'quota'
[ju]	viuda	'widow'

Italian

In standard Italian, only falling diphthongs are considered to be true diphthongs. Rising diphthongs are considered to be sequences of approximant and vowel.^{[citation needed]} The diphthongs of Italian are:^[24]

Italian diphthongs

falling
[ai̯]	baita	'mountain hut'	[au̯]	auto	'car'
[ei̯]	potei	'I could'	[eu̯]	pleurite	'pleurisy'
[ɛi̯]	sei	'six'	[ɛu̯]	neutro	'neuter'
[ɔi̯]	poi	'later'
[oi̯]	voi	'you' (pl.)
[ui̯]	lui	'he'
rising
[ja]	chiave	'key'	[wa]	guado	'ford'
[jɛ]	pieno	'full'	[wɛ]	quercia	'oak'
[je]	soffietto	'bellows'	[we]	quello	'that'
			[wi]	guida	'guide'
[jɔ]	chiodo	'nail'	[wɔ]	quota	'quota'
[jo]	fiore	'flower'	[wo]	acquoso	'watery'
[ju]	piuma	'feather'

In general, unstressed /i e o u/ in hiatus can turn into glides in more rapid speech (e.g. biennale [bi̯enˈnaːle] 'biennial'; coalizione [ko̯alitˈtsi̯oːne] 'coalition') with the process occurring more readily in syllables further from stress.^[25]

Romanian

Main article: Romanian phonology

Romanian has two diphthongs: /e̯a/ and /o̯a/. As a result of their origin (diphthongization of mid vowels under stress), they appear only in stressed syllables^[26] and make morphological alternations with the mid vowels /e/ and /o/. To native speakers, they sound very similar to /ja/ and /wa/ respectively.^[27] There are no perfect minimal pairs to contrast /o̯a/ and /wa/,^[3] and because /o̯a/ doesn't appear in the final syllable of a prosodic word, there are no monosyllabic words with /o̯a/; exceptions might include voal ('veil') and trotuar ('sidewalk'), though Ioana Chiţoran argues^[28] that these are best treated as containing glide-vowel sequences rather than diphthongs. In addition to these, the semivowels /j/ and /w/ can be combined (either before, after, or both) with most vowels, while this arguably^[29] forms additional diphthongs and triphthongs, only /e̯a/ and /o̯a/ can follow an obstruent-liquid cluster such as in broască ('frog') and dreagă ('to mend').^[30] implying that /j/ and /w/ are restricted to the syllable boundary and therefore, strictly speaking, do not form diphthongs.

Celtic languages

Irish

All Irish diphthongs are falling.

• [əi̯], spelled aigh, aidh, agh, adh, eagh, eadh, eigh, or eidh
• [əu̯], spelled abh, amh, eabh, or eamh
• [iə̯], spelled ia, iai
• [uə̯], spelled ua, uai

Slavic languages

Croatian

• i(j)e, as in mlijeko^[31]

is conventionally considered a diphthong. However, it is actually [ie] in hiatus or separated by a semivowel, [ije].

Croatian dialects also have uo, as in kuonj, ruod, uon^[32] while, in Standard Croatian, these words are konj, rod, on)

Czech

There are three diphthongs in Czech:

• /aʊ̯/ as in auto (almost exclusively in words of foreign origin)
• /eʊ̯/ as in euro (in words of foreign origin only)
• /oʊ̯/ as in koule

The vowel groups ia, ie, ii, io, and iu in foreign words are not regarded as diphthongs, they are pronounced with /j/ between the vowels [ɪja, ɪjɛ, ɪjɪ, ɪjo, ɪju].

Finno-Ugric languages

Estonian

Main article: Estonian phonology

All nine vowels can appear as the first component of an Estonian diphthong, but only [ɑ e i o u] occur as the second component.

Common Estonian diphthongs

		[ɑe]	aed "fence, garden"	[ɑi]	lai "wide"	[ɑo]	kaotama "to lose"	[ɑu]	laud "table"
[eɑ]	teadma "to know"			[ei]	leib "bread"	[eo]	teostus "accomplishment"	[iu]	kiuste "in spite of"
[oɑ]	toa "room" (s. possessive)	[oe]	koer "dog"	[oi]	toit "food"
				[ui]	kui "when, if"
		[ɤe]	nõel "needle"	[ɤi]	õige "right, correct"	[ɤo]	tõotus "promise"	[ɤu]	lõug "chin"
		[æe]	päev "day"	[æi]	täis "full"	[æo]	näo "face" (s. possessive)
		[øe]	söed "coals"	[øi]	köis "rope"

There are additional diphthongs less commonly used, such as [eu] in Euroopa (Europe), [øɑ] in söandama (to dare), and [æu] in näuguma (to mew).

Finnish

Main article: Finnish phonology

All Finnish diphthongs are falling. Notably, Finnish has true opening diphthongs (e.g. /uo/), which are not very common crosslinguistically compared to centering diphthongs (e.g. /uə/ in English). Vowel combinations across syllables may in practice be pronounced as diphthongs, when an intervening consonant has elided, e.g. in näön [næøn] instead of [næ.øn] < genitive of näkö "sight".

closing

• [ɑi̯] as in laiva (ship)
• [ei̯] as in keinu (swing)
• [oi̯] as in poika (boy)
• [æi̯] as in äiti (mother)
• [øi̯] as in öisin (at nights)
• [ɑu̯] as in lauha (mild)
• [eu̯] as in leuto (mild)
• [ou̯] as in koulu (school)
• [ey̯] as in leyhyä (to waft)
• [æy̯] as in täysi (full)
• [øy̯] as in löytää (to find)

close

• [ui̯] as in uida (to swim)
• [yi̯] as in lyijy (lead)
• [iu̯] as in viulu (violin)
• [iy̯] as in siistiytyä (to smarten up)

opening

• [ie̯] as in kieli (tongue)
• [uo̯] as in suo (bog)
• [yø̯] as in yö (night)

Northern Sami

The diphthong system in Northern Sami varies considerably from one dialect to another. The Western Finnmark dialects distinguish four different qualities of opening diphthongs:

• /eæ/ as in leat "to be"
• /ie/ as in giella "language"
• /oa/ as in boahtit "to come"
• /uo/ as in vuodjat "to swim"

In terms of quantity, Northern Sami shows a three-way contrast between long, short and finally stressed diphthongs. The last are distinguished from long and short diphthongs by a markedly long and stressed second component. Diphthong quantity is not indicated in spelling.

Semitic languages

Maltese

Maltese has seven falling diphthongs, though they may be considered VC sequences phonemically.^[33]

• [ɛɪ̯] ej or għi
• [ɐɪ̯] aj or għi
• [ɔɪ̯] oj
• [ɪʊ̯] iw
• [ɛʊ̯] ew
• [ɐʊ̯] aw or għu
• [ɔʊ̯] ow or għu

Sino-Tibetan languages

Mandarin Chinese

Rising sequences in Mandarin are usually regarded as a combination of a medial semivowel ([j], [w], or [ɥ]) plus a vowel, while falling sequences are regarded as one diphthong.

• ai: [aɪ̯], as in ài (愛, love)
• ei: [eɪ̯], as in lèi (累, tired)
• ao: [ɑʊ̯], as in dào (道, way)
• ou: [oʊ̯], as in dòu (豆, bean)

However, the four rising sequences below can be considered diphthongs as they are analogous to [ɨ], [i], [u] and [y] respectively and the bare vowel nucleus mostly only occurs along with the corresponding medial.

• e: [ɰʌ], as in hē (喝, to drink)
• ye/-ie: [jɛ], as in xié (斜, tilted)
• wo/-uo: [wɔ], as in wǒ (我, I)
• yue/-üe: [ɥœ], as in yuè (月, moon)

Tai–Kadai languages

Thai

In addition to vowel nuclei following or preceding /j/ and /w/, Thai has three diphthongs:^[34]

• [iɐ̯]
• [ɯɐ̯]
• [uɐ̯]

Bantu languages

Zulu

Zulu has only monophthongs. Y and w are semi-vowels:

• [ja] as in [ŋijaɠuˈɓɛːɠa] ngiyakubeka (I am placing it)
• [wa] as in [ŋiːwa] ngiwa (I fall/I am falling)

See also

• Hiatus
• Index of phonetics articles
• Table of vowels
• Monophthong
• Semivowel
• Triphthong
• Vowel
• Vowel cluster
• Vowel breaking
• Diaeresis

References

1. ^ "diphthong". Dictionary.com Unabridged. Random House, Inc. http://dictionary.reference.com/browse/diphthong. 
2. ^ definition of 'Diphthong' on SIL International, accessed 17 January 2008
3. ^ ^{a b} Chițoran (2002a:203)
4. ^ Kaye & Lowenstamm (1984:139)
5. ^ Schane (1995:588)
6. ^ Padgett (2007:1938)
7. ^ Schane (1995:606)
8. ^ Schane (1995:589, 606)
9. ^ Gussenhoven (1992:46)
10. ^ Verhoeven (2005:245)
11. ^ Verhoeven (2007:221)
12. ^ Kleine (2003:263)
13. ^ Chitoran (2001:11)
14. ^ Carbonell & Llisterri (1992:54)
15. ^ Institut d'Estudis Catalans Els diftongs, els triftongs i els hiats – Gramàtica de la Llengua Catalana (provisional draft)
16. ^ e.g. Lleó (1970), Wheeler (1979)
17. ^ Wheeler (2005:101)
18. ^ Mascaró (2002:580–581)
19. ^ Mascaró (2002:581)
20. ^ Faria (2003:7)
21. ^ ^{a b} Cruz-Ferreira (1995:92)
22. ^ ^{a b} Barbosa & Albano (2004:230)
23. ^ Martínez-Celdrán, Fernández-Planas & Carrera-Sabaté (2003:256)
24. ^ Bertinetto & Loporcaro (2005:138)
25. ^ Bertinetto & Loporcaro (2005:139)
26. ^ Chițoran (2002a:204)
27. ^ Chițoran (2002a:206)
28. ^ Chițoran (2002b:217)
29. ^ See Chițoran (2001:8–9) for a brief overview of the views regarding Romanian semivowels
30. ^ Chițoran (2002b:213)
31. ^ (Croatian) Vjesnik Babić ne zagovara korijenski pravopis, nego traži da Hrvati ne piju mlijeko nego – mlieko
32. ^ (Croatian) Kolo Josip Lisac: Štokavsko narječje: prostiranje i osnovne značajke
33. ^ Borg & Azzopardi-Alexander (1997:299)
34. ^ Tingsabadh & Abramson (1993:25)

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