Click consonant

ʘ ǀ ǁ ǂ ǃ 𝼊
Click releases
InUnicode	U+0298ʘLATIN LETTER BILABIAL CLICK U+01C0ǀLATIN LETTER DENTAL CLICK U+01C1ǁLATIN LETTER LATERAL CLICK U+01C2ǂLATIN LETTER ALVEOLAR CLICK U+01C3ǃLATIN LETTER RETROFLEX CLICK U+01DF0A𝼊LATIN LETTER RETROFLEX CLICK WITH RETROFLEX HOOK
Different from
Different from	U+007C|VERTICAL LINE U+2016‖DOUBLE VERTICAL LINE U+0021!EXCLAMATION MARK

Click consonants,orclicks,are speech sounds that occur asconsonantsin many languages ofSouthern Africaand in three languages ofEast Africa.Examples familiar toEnglish-speakersare thetut-tut(British spelling) ortsk! tsk!(American spelling) used to express disapproval or pity (IPA[ǀ]), thetchick!used to spur on a horse (IPA[ǁ]), and theclip-clop!sound children make with their tongue to imitate a horse trotting (IPA[ǃ]). However, theseparalinguisticsounds in English are not full click consonants, as they only involve the front of the tongue, without the release of the back of the tongue that is required for clicks to combine with vowels and form syllables.

Anatomically, clicks areobstruentsarticulated with two closures (points of contact) in the mouth, one forward and one at the back. The enclosed pocket of air israrefiedby a sucking action of the tongue (in technical terminology, clicks have alingual ingressive airstream mechanism). The forward closure is then released,producing what may be the loudest consonants in the language, although in some languages such asHadzaandSandawe,clicks can be more subtle and may even be mistaken forejectives.

Phonetics and IPA notation

Click consonants occur at six principal places of articulation. TheInternational Phonetic Alphabet (IPA)provides five letters for these places (there is as yet no dedicated symbol for the sixth).

• The easiest clicks for English speakers are thedental clickswritten with a single pipe, ⟨ǀ⟩. These are sharp (high-pitched) squeaky sounds made by sucking on the front teeth. A simple dental click is used in English to express pity or to shame someone, or to call a cat or other animal, and is writtentut!in British English andtsk!in American English. In many cultures around the Mediterranean a simple dental click is used for "no" in answer to a direct question. They are written with the lettercinZuluandXhosa.
• Next most familiar to English speakers are thelateral clicks,which are written with a double pipe, ⟨ǁ⟩. They are also squeaky sounds, though less sharp than[ǀ],made by sucking on the molars on either side (or both sides) of the mouth. A simple lateral click is made in English to get a horse moving, and is conventionally writtentchick!.They are written with the letterxin Zulu and Xhosa.
• Then there are thelabial clicks,written with a bull's eye, ⟨ʘ⟩. These are lip-smacking sounds, but often without the pursing of the lips found in a kiss, that occur in words in only a few languages.

The above clicks sound likeaffricates,in that they involve a lot of friction. The next two families of clicks are more abrupt sounds that do not have this friction.

• With thealveolar clicks,written with an exclamation mark, ⟨ǃ⟩, the tip of the tongue is pulled down abruptly and forcefully from the roof of the mouth, sometimes using a lot of jaw motion, and making a hollowpop!like a cork being pulled from an empty bottle. Something like these sounds may be used for a 'clip-clop' sound as noted above. These sounds can be quite loud. They are written with the letterqin Zulu and Xhosa.
• Thepalatal clicks,⟨ǂ⟩, are made with a flat tongue that is pulled backward rather than downward, and are sharper cracking sounds than the[ǃ]clicks, like sharply snapped fingers. They are not found in Zulu but are very common in the San languages of southern Africa.
• Finally, theretroflex clicksare poorly known, being attested from only a single language,Central!Kung.The tongue is curled back in the mouth, and they are both fricative and hollow sounding, but descriptions of these sounds vary between sources. This may reflect dialect differences. They are perhaps most commonly written ⟨‼⟩, but that is anad hoctranscription. The expected IPA letter is ⟨𝼊⟩ (⟨ǃ⟩ with retroflex tail), and the IPA supported the addition of that letter to Unicode.

Technically, these IPA letters transcribe only the forward articulation of the click, not the entire consonant. As theHandbookstates,

Since any click involves a velar or uvular closure [as well], it is possible to symbolize factors such as voicelessness, voicing or nasality of the click by combining the click symbol with the appropriate velar or uvular symbol:[k͡ǂɡ͡ǂŋ͡ǂ],[q͡ǃ].

Thus technically[ǂ]is not a consonant, but only one part of the articulation of a consonant, and one may speak of "ǂ-clicks" to mean any of the various click consonants that share the[ǂ]place of articulation.In practice, however, the simple letter ⟨ǂ⟩ has long been used as an abbreviation for[k͡ǂ],and in that role it is sometimes seen combined with diacritics for voicing (e.g. ⟨ǂ̬⟩ for[ɡ͡ǂ]), nasalization (e.g. ⟨ǂ̃⟩ for[ŋ͡ǂ]), etc. These differing transcription conventions may reflect differing theoretical analyses of the nature of click consonants, or attempts to address common misunderstandings of clicks.

Languages with clicks

Southern Africa

Clicks occur in all threeKhoisan language familiesofsouthern Africa,where they may be the most numerous consonants. To a lesser extent they occur in three neighbouring groups ofBantu languages—whichborrowed them,directly or indirectly, from Khoisan. In the southeast, in easternSouth Africa,Eswatini,Lesotho,Zimbabweand southernMozambique,they were adopted from aTuu language(or languages) by the languages of the Nguni cluster (especiallyZulu,XhosaandPhuthi,but also to a lesser extentSwaziandNdebele), and spread from them in a reduced fashion to the Zulu-basedpidginFanagalo,Sesotho,Tsonga,Ronga,the Mzimba dialect ofTumbukaand more recently toNdauand urban varieties ofPedi,where the spread of clicks continues. The second point of transfer was near theCaprivi Stripand theOkavango Riverwhere, apparently, theYeyi languageborrowed the clicks from aWest Kalahari Khoe language;a separate development led to a smaller click inventory in the neighbouringMbukushu,Kwangali,Gciriku,KuhaneandFwelanguages inAngola,Namibia,BotswanaandZambia.These sounds occur not only in borrowed vocabulary, but have spread to native Bantu words as well, in the case of Nguni at least partially due to a type of word taboo calledhlonipha.Somecreolisedvarieties of Afrikaans, such asOorlams,retain clicks inKhoekhoewords.

East Africa

Three languages inEast Africause clicks:SandaweandHadzaofTanzania,andDahalo,an endangered SouthCushitic languageofKenyathat has clicks in only a few dozen words. It is thought the latter may remain from an episode oflanguage shift.

Damin

The only non-African language known to have clicks as regular speech sounds isDamin,a ritual code once used by speakers ofLardilinAustralia.In addition, one consonant in Damin is theegressiveequivalent of a click, using the tongue to compress the air in the mouth for an outward (egressive) "spurt".

Use

Spread of clicks from loanwords

Once clicks are borrowed into a language as regular speech sounds, they may spread to native words, as has happened due tohlonipaword-taboo in theNguni languages.InGciriku,for example, the European loanwordtomate(tomato) appears ascumátewith a click[ǀ],though it begins with atin all neighbouring languages. It has also been argued that click phonemes have been adopted into some languages through the process ofhlonipha,women refraining from saying certain words and sounds that were similar to the name of their husband, sometimes replacing local sounds by borrowing clicks from a nearby language.

Marginal usage of clicks

Scattered clicks are found inideophonesand mimesis in other languages, such asKongo/ᵑǃ/,Mijikenda/ᵑǀ/and Hadza/ᵑʘʷ/(Hadza does not otherwise have labial clicks). Ideophones often use phonemic distinctions not found in normal vocabulary.

English and many other languages may use bare click releases ininterjections,without an accompanying rear release or transition into a vowel, such as the dental "tsk-tsk" sound used to express disapproval, or the lateraltchickused with horses. In a number of languages ranging from the central Mediterranean to Iran,a bare dental click release accompanied by tipping the head upwards signifies "no".Libyan Arabicapparently has three such sounds.A voiceless nasalback-released velar click[ʞ]is used throughout Africa forbackchanneling.This sound starts off as a typical click, but the action is reversed and it is the rear velar or uvular closure that is released, drawing in air from the throat and nasal passages.

Clicks occasionally turn up elsewhere, as in the specialregisterstwins sometimes develop with each other. InWest Africa,clicks have been reported allophonically, and similarly in French and German, faint clicks have been recorded in rapid speech where consonants such as/t/and/k/overlap between words.InRwanda,the sequence/mŋ/may be pronounced either with an epenthetic vowel,[mᵊ̃ŋ],or with a light bilabial click,[m𐞵̃ŋ]—often by the same speaker.

Speakers ofGan ChinesefromNingducounty, as well as speakers of Mandarin from Beijing andJilinand presumably people from other parts of the country, produce flapped nasal clicks in nursery rhymes with varying degrees of competence, in the words for 'goose' and 'duck', both of which begin with/ŋ/in Gan and until recently began with/ŋ/in Mandarin as well. In Gan, the nursery rhyme is,

[tʰienitsʰakᵑǃ¡o]Bầu trời một con ngỗng 'a goose in the sky'

[tihaitsʰakᵑǃ¡a]Ngầm một con vịt 'a duck on the ground'

[ᵑǃ¡osaŋᵑǃ¡otʰan,ᵑǃ¡opʰauᵑǃ¡o]Ngỗng sinh trứng ngỗng ngỗng ấp ngỗng 'a goose lays a goose egg, a goose hatches a goose'

[ᵑǃ¡asaŋᵑǃ¡atʰan,ᵑǃ¡apʰauᵑǃ¡a]Vịt sinh trứng vịt vịt ấp vịt 'a duck lays a duck egg, a duck hatches a duck'

where the/ŋ/onsets are all pronounced[ᵑǃ¡].

Occasionally other languages are claimed to have click sounds in general vocabulary. This is usually a misnomer forejective consonants,which are found across much of the world.

Position in word

See also:§ Phonotactics

For the most part, the Southern AfricanKhoisan languagesonly useroot-initial clicks.Hadza, Sandawe and severalBantu languagesalso allowsyllable-initial clicks within roots. In no language does a click close a syllable or end a word, but since the languages of the world that happen to have clicks consist mostly of CV syllables and allow at most only a limited set of consonants (such as a nasal or a glottal stop) to close a syllable or end a word,mostconsonants share the distribution of clicks in these languages.

Number of click-types in languages

Most languages of the Khoesan families (Tuu, Kxʼa and Khoe) have four click types:{ ǀǁǃǂ } or variants thereof, though a few have three or five, the last supplemented with eitherbilabial{ ʘ } orretroflex{ 𝼊 }. Hadza and Sandawe in Tanzania have three,{ ǀǁǃ }. Yeyi is the only Bantu language with four,{ ǀǁǃǂ }, while Xhosa and Zulu have three,{ ǀǁǃ }, and most other Bantu languages with clicks have fewer.

Types of clicks

Like other consonants, clicks can be described using four parameters:place of articulation,manner of articulation,phonation(including glottalisation) andairstream mechanism.As noted above, clicks necessarily involve at least two closures, which in some cases operate partially independently: an anterior articulation traditionally represented by the special click symbol in the IPA—and a posterior articulation traditionally transcribed for convenience as oral ornasal,voiced or voiceless, though such features actually apply to the entire consonant. The literature also describes a contrast betweenvelaranduvularrear articulations for some languages.

In some languages that have been reported to make this distinction, such asNǁng,all clicks have a uvular rear closure, and the clicks explicitly described as uvular are in fact cases where the uvular closure is independently audible: contours of a click into a pulmonic or ejective component, in which the click has two release bursts, the forward (click-type) and then the rearward (uvular) component. "Velar" clicks in these languages have only a single release burst, that of the forward release, and the release of the rear articulation isn't audible. However, in other languages all clicks are velar, and a few languages, such asTaa,have a true velar–uvular distinction that depends on the place rather than the timing of rear articulation and that is audible in the quality of the vowel.

Regardless, in most of the literature the stated place of the click is the anterior articulation (called thereleaseorinflux),whereas the manner is ascribed to the posterior articulation (called theaccompanimentorefflux).The anterior articulation defines theclick typeand is written with the IPA letter for the click (dental ⟨ǀ⟩, alveolar ⟨ǃ⟩, etc.), whereas the traditional term 'accompaniment' conflates the categories of manner (nasal, affricated), phonation (voiced, aspirated, breathy voiced, glottalised), as well as any change in the airstream with the release of the posterior articulation (pulmonic, ejective), all of which are transcribed with additional letters or diacritics, as in thenasal alveolar click,⟨ǃŋ⟩ or ⟨ᵑǃ⟩ or—to take an extreme example—thevoiced (uvular) ejective alveolar click,⟨ᶢǃ͡qʼ⟩.

The size of click inventories ranges from as few as three (inSesotho) or four (inDahalo), to dozens in theKxʼaandTuu(Northern and Southern Khoisan) languages.Taa,the last vibrant language in the latter family, has 45 to 115 click phonemes, depending on analysis (clusters vs. contours), and over 70% of words in the dictionary of this language begin with a click.

Clicks appear morestop-like (sharp/abrupt) oraffricate-like (noisy) depending on their place of articulation: In southern Africa, clicks involving anapicalalveolarorlaminalpostalveolarclosure are acoustically abrupt and sharp, like stops, whereaslabial,dentalandlateralclicks typically have longer and acoustically noisier click types that are superficially more like affricates. In East Africa, however, the alveolar clicks tend to beflapped,whereas the lateral clicks tend to be more sharp.

Transcription

Further information:click letter

The five click places of articulation with dedicated symbols in theInternational Phonetic Alphabet(IPA) arelabialʘ,dentalǀ,palatal( "palato-alveolar" )ǂ,(post)alveolar( "retroflex" )ǃandlateralǁ.In most languages, the alveolar and palatal types are abrupt; that is, they are sharp popping sounds with little frication (turbulent airflow). The labial, dental and lateral types, on the other hand, are typically noisy: they are longer, lip- or tooth-sucking sounds with turbulent airflow, and are sometimes called affricates. (This applies to the forward articulation; both may also have either an affricate or non-affricate rear articulation as well.) Theapicalplaces,ǃandǁ,are sometimes called "grave", because their pitch is dominated by low frequencies; whereas thelaminalplaces,ǀandǂ,are sometimes called "acute", because they are dominated by high frequencies. (At least in theNǁng languageandJuǀʼhoan,this is associated with a difference in the placement of the rear articulation: "grave" clicks areuvular,whereas "acute" clicks arepharyngeal.) Thus the alveolar click/ǃ/sounds something like a cork pulled from a bottle (a low-pitch pop), at least in Xhosa; whereas the dental click/ǀ/is like Englishtsk! tsk!,a high-pitched sucking on the incisors. The lateral clicks are pronounced by sucking on the molars of one or both sides. The labial click/ʘ/is different from what many people associate with a kiss: the lips are pressed more-or-less flat together, as they are for a[p]or an[m],not rounded as they are for a[w].

The most populous languages with clicks, Zulu and Xhosa, use the lettersc, q, x,by themselves and indigraphs,to write click consonants. Most Khoisan languages, on the other hand (with the notable exceptions ofNaroandSandawe), use a more iconic system based on thepipe⟨|⟩.(The exclamation point for the "retroflex" click was originally a pipe with a subscript dot, along the lines ofṭ, ḍ, ṇused to transcribe the retroflex consonants of India.) There are also two main conventions for the second letter of the digraph as well: voicing may be written withgand uvular affrication withx,or voicing withdand affrication withg(a convention of Afrikaans). In two orthographies of Juǀʼhoan, for example, voiced/ᶢǃ/is writteng!ordq,and/ᵏǃ͡χ/!xorqg.In languages without/ᵏǃ͡χ/,such as Zulu,/ᶢǃ/may be writtengq.

Competing orthographies

	labial	laminal		apical		subapical
		dental	palatal	alveolar	lateral	retroflex
Lepsius (1855)		ǀ	ǀ́	ǀ̣	ǀǀ
Doke (1926)		ʇ	🡣a	ʗ	ʖ	ψ
Beach (1938)	ʘ	ʇ	𝼋	ʗ	ʖ
Bantuist	pc	c	vçtc qcb	q	x
IPA	ʘ	ǀ	ǂ	ǃ	ǁ	𝼊

1. ^a⟨🡣⟩was proposed byClement Doke,and𝼋byBeach,but did not catch on. The former is not supported by Unicode, and the latter was proposed only in 2020. (Doke's character resembles a down arrow and is here represented by the oldRoman numeralfor 50;Beach is a double-barredesh.) Three of these, ⟨ʇ⟩, ⟨ʗ⟩ and ⟨ʖ⟩, were adopted into the IPA, though eventually abandoned. Doke and Beach usedadditional or modified lettersfor voiced and nasal clicks, but they did not catch on.
2. ^bThe labial and palatal clicks do not occur in written Bantu languages. However, the palatal clicks have been romanised in Naron,Juǀʼhõasiand!Xun,where they have been written⟨tc⟩,⟨ç⟩and⟨qc⟩,respectively. In the 19th century, they were sometimes written⟨v⟩,which might be source of the Doke letter⟨🡣⟩.

There are a few less-well-attested articulations. A reported subapical retroflex articulation ⟨𝼊⟩ in Grootfontein!Kungturns out to be alveolar with lateral release, ⟨ǃ𐞷⟩; Ekoka!Kung has a fricated alveolar click with an s-like release, provisionally transcribed ⟨ǃ͡s⟩; and Sandawe has a "slapped" alveolar click, provisionally transcribed ⟨ǃ¡⟩ (in turn, the lateral clicks in Sandawe are more abrupt and less noisy than in southern Africa). However, the Khoisan languages are poorly attested, and it is quite possible that, as they become better described, more click articulations will be found.

Formerly when a click consonant was transcribed, two symbols were used, one for each articulation, and connected with a tie bar. This is because a click such as[ɢ͡ǀ]was analysed as a voiced uvular rear articulation[ɢ]pronounced simultaneously with the forward ingressive release[ǀ].The symbols may be written in either order, depending on the analysis: ⟨ɢ͡ǀ⟩ or ⟨ǀ͡ɢ⟩. However, a tie bar was not often used in practice, and when the manner istenuis(a simple[k]), it was often omitted as well. That is, ⟨ǂ⟩ = ⟨kǂ⟩ = ⟨ǂk⟩ = ⟨k͡ǂ⟩ = ⟨ǂ͡k⟩. Regardless, elements that do not overlap with the forward release are usually written according to their temporal order: Prenasalisation is always written first (⟨ɴɢ͡ǀ⟩ = ⟨ɴǀ͡ɢ⟩ = ⟨ɴǀ̬⟩), and the non-lingual part of a contour is always written second (⟨k͡ǀʼqʼ⟩ = ⟨ǀ͡kʼqʼ⟩ = ⟨ǀ͡qʼ⟩).

However, it is common to analyse clicks as simplex segments, despite the fact that the front and rear articulations are independent, and to use diacritics to indicate the rear articulation and the accompaniment. At first this tended to be ⟨ᵏǀ, ᶢǀ, ᵑǀ⟩ for ⟨k͡ǀ, ɡ͡ǀ, ŋ͡ǀ⟩, based on the belief that the rear articulation was velar; but as it has become clear that the rear articulation is often uvular or even pharyngeal even when there is no velar–uvular contrast, voicing and nasalisation diacritics more in keeping with the IPA have started to appear: ⟨ǀ̥, ǀ̬, ǀ̃, ŋǀ̬⟩ for ⟨ᵏǀ, ᶢǀ, ᵑǀ, ŋᶢǀ⟩.

Variation in the transcription of accompaniments

	Tenuis	Aspirated	Voiced	Nasal	Delayed ( "uvular" )	True uvular
Tie bars	k͡ǀ	k͡ǀʰ	ɡ͡ǀ	ŋ͡ǀ	ǀ͡k,ǀ͡kʰ,ǀ͡ɡ,ǀ͡ŋ	q͡ǀ,ǀ͡qetc.
Digraphs	kǀ	kǀʰ	ɡǀ	ŋǀ	ǀk,ǀkʰ,ǀɡ,ǀŋ	qǀ,ǀqetc.
Superscripts	ᵏǀ	ᵏǀʰ	ᶢǀ	ᵑǀ	ǀᵏ,ǀᵏʰ,ǀᶢ,ǀᵑ	qǀ,ǀqetc.
Diacritics	ǀ̥	ǀʰ	ǀ̬	ǀ̬̃	NA	NA

In practical orthography, the voicing or nasalisation is sometimes given the anterior place of articulation:dcforᶢǀandmʘforᵑʘ,for example.

In the literature on Damin, the clicks are transcribed by adding⟨!⟩to the homorganic nasal:⟨m!, nh!, n!, rn!⟩.

Places of articulation

Main articles:bilabial click,dental click,palatal click,alveolar click,lateral click,retroflex click,andvelar click

Places of articulationare often called clicktypes, releases,orinfluxes,though 'release' is also used for the accompaniment/efflux. There are seven or eight known places of articulation, not counting slapped or egressive clicks. These are(bi)labial affricatedʘ,or "bilabial";laminal denti-alveolar affricatedǀ,or "dental";apical (post)alveolar plosiveǃ,or "alveolar";laminal palatal plosiveǂ,or "palatal";laminal palatal affricatedǂᶴ(known only fromEkoka!Kung);subapical postalveolar𝼊,or "retroflex"(only known fromCentral!Kungand possibly Damin); andapical (post)alveolar lateralǁ,or "lateral".

Place of articulation of initial release

Labial	Dental	Alveolar	Slapped	Retroflex	Domed	Palatal	Lateral	Linguolabial	Velar
ʘ	ǀ	ǃ	ǃ¡	𝼊	ǂᶴ(𝼋)	ǂ	ǁ	ǀ̼	ʞ
			(allophonic)					(paralexical only)

Languages illustrating each of these articulations are listed below. Given the poor state of documentation of Khoisan languages, it is quite possible that additional places of articulation will turn up. No language is known to contrast more than five.

Click place inventory	Languages	Notes
1 release, variableǀ~ǁ	Dahalo	Various nasal clicks only.
1 release, variableǀ~ǃ	Sotho,Swazi	In Sotho the clicks tend to be alveolar, in Swazi dental.
1 release, variableǀ~ǃ~ǁorǂ	Fwe,Gciriku	Tend to be dental.
3 releases,ǀ,ǂ,ǁ	Kwadi	ǂandǁnot found with all manners, but these may be accidental gaps, as Kwadi is poorly attested
3 releases,ǀ,ǃ,ǁ	Sandawe,Hadza,Xhosa,Zulu	In Sandawe,ǃis often "slapped"[ǃ¡].
3–4 releases,ʘ,ǀ,(ǃ,)ǁ	ǁXegwi	ǃreacquired in loans
4 releases,ǀ,ǂ,ǃ,ǁ	Korana,Khoekhoe,Yeyi,Juǀʼhoan
4 releases,ǀ,ǂᶴ,ǃ,ǁ	Ekoka!Kung
5 releases,ʘ,ǀ,ǂ,ǃ,ǁ	ǂHõã,Nǀu,ǀXam,Taa
5 releases,ǀ,ǂ,ǃ,𝼊,ǁ	Grootfontein!Kung
5 releases,ʘ,ʘ↑,ǀ,ǃ,𝼊	Damin	Aside from/ʘ↑/,which is not technically a click, all are nasal.

Extra-linguistically,Coatlán ZapotecofMexicouses alinguolabialclick,[ǀ̼ʔ],asmimesisfor a pig drinking water,and several languages, such asWolof,use avelar click[ʞ],long judged to be physically impossible, forbackchannelingand to express approval.An extended dental click with lip pursing or compression ( "sucking-teeth"), variable in sound and sometimes described as intermediate between[ǀ]and[ʘ],is found across West Africa, the Caribbean and into the United States.

The exact place of the alveolar clicks varies between languages. The lateral, for example, is alveolar in Khoekhoe but postalveolar or even palatal in Sandawe; the central is alveolar in Nǀuu but postalveolar in Juǀʼhoan.

Names found in the literature

The terms for the click types were originally developed by Bleek in 1862.Since then there has been some conflicting variation. However, apart from "cerebral" (retroflex), which was found to be an inaccurate label when true retroflex clicks were discovered, Bleek's terms are still considered normative today. Here are the terms used in some of the main references.

Names in the literature

Click type	Bleek (1862)	Doke (1926)	IPA (1928)	Beach (1938)	IPA (1949)	IPA (1989)	Unicode	Miller et al. (2009)	Vossen (2013)	other
ǀ	dental	dental	dental	dental affricative	dental	dental	dental	denti-pharyngeal	dental	alveolar affricated; denti-alveolar; apico-lamino-dental
ǃ	cerebral	palato-alveolar	cerebral	alveolar implosive	retroflex	(post-)alveolar	retroflex	central alveo-uvular	alveolar	palatal; palatal retroflex; apico-palatal
ǁ	lateral	lateral	alveolar lateral	lateral affricative	lateral	(alveolar) lateral	lateral	lateral alveo-uvular	lateral-alveolar	post-alveolar lateral; lateral apico-alveo-palatal
ǂ	palatal	alveolar	velar	denti-alveolar implosive	velar	palatoalveolar	alveolar	palato-pharyngeal	palatal	alveolar instantaneous; dental
ʘ						bilabial	bilabial	labio-uvular	bilabial	labial

The dental, lateral and bilabial clicks are rarely confused, but the palatal and alveolar clicks frequently have conflicting names in older literature, and non-standard terminology is fossilized in Unicode. However, since Ladefoged & Traill (1984) clarified the places of articulation, the terms listed under Vosser (2013) in the table above have become standard, apart from such details as whether in a particular languageǃandǁare alveolar or postalveolar, or whether the rear articulation is velar, uvular or pharyngeal, which again varies between languages (or may even be contrastive within a language).

Manners of articulation

Main articles:nasal click,glottalised click,pulmonic-contour click,andejective-contour click

Click manners are often called clickaccompanimentsoreffluxes,but both terms have met with objections on theoretical grounds.

There is a great variety of click manners, both simplex and complex, the latter variously analysed as consonantclustersorcontours.With so few click languages, and so little study of them, it is also unclear to what extent clicks in different languages are equivalent. For example, the[ǃkˀ]of Khoekhoe,[ǃkˀ~ŋˀǃk]of Sandawe and[ŋ̊ǃˀ~ŋǃkˀ]of Hadza may be essentially the same phone; no language distinguishes them, and the differences in transcription may have more to do with the approach of the linguist than with actual differences in the sounds. Such suspected allophones/allographs are listed on a common row in the table below.

Some Khoisan languages aretypologicallyunusual in allowing mixedvoicingin non-click consonant clusters/contours, such as̬d̥sʼk͡x,so it is not surprising that they would allow mixed voicing in clicks as well. This may be an effect of epiglottalised voiced consonants, because voicing is incompatible with epiglottalisation.

Phonation

As do other consonants, clicks vary inphonation.Oral clicks are attested with four phonations:tenuis,aspirated,voicedandbreathy voiced(murmured). Nasal clicks may also vary, with plain voiced, breathy voiced / murmured nasal, aspirated and unaspirated voiceless clicks attested (the last only in Taa). The aspirated nasal clicks are often said to have 'delayed aspiration'; there is nasal airflow throughout the click, which may become voiced between vowels, though the aspiration itself is voiceless. A few languages also have pre-glottalised nasal clicks, which have very brief prenasalisation but have not been phonetically analysed to the extent that other types of clicks have.

All languages have nasal clicks, and all butDahaloandDaminalso have oral clicks. All languages but Damin have at least one phonation contrast as well.

Complex clicks

Clicks may be pronounced with a third place of articulation, glottal. Aglottal stopis made during the hold of the click; the (necessarily voiceless) click is released, and then the glottal hold is released into the vowel. Glottalised clicks are very common, and they are generally nasalised as well. The nasalisation cannot be heard during the click release, as there is no pulmonic airflow, and generally not at all when the click occurs at the beginning of an utterance, but it has the effect of nasalising preceding vowels, to the extent that the glottalised clicks of Sandawe and Hadza are often described as prenasalised when in medial position. Two languages,GǀwiandYeyi,contrast plain and nasal glottalised clicks, but in languages without such a contrast, the glottalised click is nasal. Miller (2011) analyses the glottalisation as phonation, and so considers these to be simple clicks.

Various languages also have prenasalised clicks, which may be analysed as consonant sequences.Sotho,for example, allows a syllabic nasal before its three clicks, as innnqane'the other side' (prenasalised nasal) andseqhenqha'hunk'.

There is ongoing discussion as to how the distinction between what were historically described as 'velar' and 'uvular' clicks is best described. The 'uvular' clicks are only found in some languages, and have an extended pronunciation that suggests that they are more complex than the simple ('velar') clicks, which are found in all. Nakagawa (1996) describes the extended clicks inGǀwiasconsonant clusters,sequences equivalent to Englishstorpl,whereas Miller (2011) analyses similar sounds in several languages as click–non-clickcontours,where a click transitions into a pulmonic or ejective articulation within a single segment, analogous to how Englishchandjtransition from occlusive to fricative but still behave as unitary sounds. With ejective clicks, for example, Miller finds that although the ejective release follows the click release, it is the rear closure of the click that is ejective, not an independently articulated consonant. That is, in a simple click, the release of the rear articulation is not audible, whereas in a contour click, the rear (uvular) articulation is audibly released after the front (click) articulation, resulting in a double release.

These contour clicks may belinguo-pulmonic,that is, they may transition from a click (lingual) articulation to a normal pulmonic consonant like[ɢ](e.g.[ǀ͡ɢ]); orlinguo-glottalicand transition from lingual to an ejective consonant like[qʼ](e.g.[ǀ͡qʼ]): that is, a sequence of ingressive (lingual) release + egressive (pulmonic or glottalic) release. In some cases there is a shift in place of articulation as well, and instead of a uvular release, the uvular click transitions to a velar orepiglottalrelease (depending on the description,[ǂ͡kxʼ]or[ǂᴴ]). Althoughhomorganic[ǂ͡χʼ]does not contrast with heterorganic[ǂ͡kxʼ]in any known language, they are phonetically quite distinct (Miller 2011).

Implosive clicks, i.e. velar[ɠ͡ʘɠ͡ǀɠ͡ǃɠ͡ǂɠ͡ǁ],uvular[ʛ͡ʘʛ͡ǀʛ͡ǃʛ͡ǂʛ͡ǁ],andde factofront-closed palatal[ʄ͡ʘʄ͡ǀʄ͡ǃʄ͡ǁ]are not only possible but easier to produce than modally voiced clicks. However, they are not attested in any language.

Apart from Dahalo, Damin and many of the Bantu languages (Yeyi and Xhosa being exceptions), 'click' languages have glottalized nasal clicks. Contour clicks are restricted to southern Africa, but are very common there: they are found in all members of the Tuu, Kxʼa and Khoe families, as well as in the Bantu language Yeyi.

Variation among languages

In a comparative study of clicks across various languages, using her own field work as well as phonetic descriptions and data by other field researchers, Miller (2011) posits 21 types of clicks that contrast in manner or airstream.Thehomorganicand heterorganic affricated ejective clicks do not contrast in any known language, but are judged dissimilar enough to keep separate. Miller's conclusions differ from those of the primary researcher of a language; see the individual languages for details.

• Taa(ǃXóõ) andNǁng(Nǀuu) areTuu languages,from the two branches of that family.
• ǂʼAmkoe(ǂHoan) andJuǀʼhoan(ǃKung) areKxʼa languages,from the two branches of that family.
• KoranaandGǀui(Gǁana) areKhoe languages,from the two branches of that family.

(all spoken primarily inSouth Africa,NamibiaandBotswana;Khoekhoeis similar to Korana except it has lost ejective/ᵏꞰ͡χʼ/)

• SandaweandHadzaarelanguage isolatesspoken inTanzania
• Dahalois aCushiticlanguage ofKenya
• XhosaandYeyiareBantu languages,from the two geographic areas of that family that have acquired clicks.

(Zuluis similar to Xhosa apart from not having/ᵑꞰˀ/)

• Daminwas an initiation jargon in northernAustralia.

Each language below is illustrated with Ʞ as a placeholder for the different click types. Under each language are the orthography (in italics, with old forms in parentheses), the researchers' transcription (in⟨angle brackets⟩), or allophonic variation (in [brackets]). Some languages also have labialised or prenasalised clicks as well as those listed below.

Language			Tuu		Kxʼa		Khoe		Sandawe	Hadza	Cushitic	Bantu		Australian
			Taa	Nǁng	ǂʼAmkoe	Juǀʼhoan	Korana	Gǀui			Dahalo	Xhosa	Yeyi	Damin
Manner			ʘ,ǂ,ǃ,ǁ,ǀ			ǂ,ǃ,ǁ,ǀ			ǃ,ǁ,ǀ		ǀ	ǃ,ǁ,ǀ	ǂ,ǃ,ǁ,ǀ	ʘ,𝼊,ǃ,ǀ
Simple oral click	Tenuis	/ᵏꞰ/	⟨Ʞ⟩*	⟨Ʞ⟩	[ᵏꞰ]	Ʞ (c, ç, q, x)	Ʞg	⟨kꞰ⟩	c, q, x	c, q, x (Ʞ)		c, q, x	⟨Ʞ⟩
	Voiced	/ᶢꞰ/	⟨gꞰ⟩*	⟨ᶢꞰ⟩	[ᶢꞰ]	gꞰ (dq etc.)		⟨gꞰ⟩	gq etc. [ᶢꞰ~ŋᶢꞰ]				⟨gꞰ⟩
	Aspirated	/ᵏꞰʰ/	⟨Ʞh⟩*	⟨Ʞʰ⟩	[ᵏꞰʰ]	Ʞh (qh etc.)	Ʞkh	⟨kꞰh⟩	qh etc.	qh etc. (Ʞh)		qh etc.	⟨Ʞh⟩(= Ʞx?)
	Breathy-voiced	/ᶢꞰʱ/	⟨gꞰh⟩*			gꞰh (dqh etc.) [ᶢꞰʱ~ᶢꞰˠ]						gq etc.
Simple nasal click	Voiceless	/ᵑ̊Ʞ/	⟨nhꞰ⟩* [ŋ̊ᵑꞰ]
	Voiced	/ᵑꞰ/	⟨nꞰ⟩* [ŋ̈ᵑꞰ]	⟨ᵑꞰ⟩	[ᵑꞰ]	nꞰ (nq etc.)	Ʞn	⟨ŋꞰ⟩	nq etc.	nq etc. (nꞰ)	/ᵑǀ/	nq etc.	⟨ŋꞰ⟩	⟨Nǃ⟩
	(Delayed) aspiration (prenasalised between vowels)	/ᵑ̊Ʞʰʱ/	⟨Ʞhh⟩ [ŋ̊↓Ʞh]	⟨ᵑ̊Ʞʰ⟩	[ᵑ̊Ʞʱ~ŋᵑ̊Ʞʱ]	Ʞʼh (qʼh etc.)	Ʞh	⟨ŋꞰh⟩
	Breathy-voiced	/ᵑꞰʱ/	⟨nꞰhh⟩			nꞰh (nqh etc.)						ngq etc.
Preglottalised nasal click		/ˀᵑꞰ/	⟨ʼnꞰ⟩*		[ʔᵑꞰ]	(in Ekoka)
Glottalised click	Oral / velar ejective	/ᵏꞰʼ/	⟨Ʞʼ⟩*					⟨kꞰʼ⟩					⟨Ʞʼ⟩
	Creaky-voiced oral	/ᶢꞰʼ/	⟨gꞰʼ⟩*
	Nasal (silent initially, prenasalised after vowels)	/ᵑ̊Ʞˀ/	⟨Ʞʼʼ⟩	⟨ᵑ̊Ʞˀ⟩	[Ʞˀ~ŋˀꞰ]	Ʞʼ (qʼ etc.) (w/ nasal vowels)	Ʞ	⟨kꞰʔ⟩(ŋ̊Ʞʔ)	qʼ etc. [Ʞˀʔ~ŋʔꞰˀ]	qq etc. (Ʞʼ ~ nꞰʼ)	/ᵑǀˀ/	nkq etc.?	⟨ŋꞰʼ⟩
	Nasal (prenasalised initially)	/ᵑꞰˀ/	⟨nꞰʼʼ⟩
Pulmonic contour	Tenuis stop	/Ʞ͡q/	⟨Ʞq⟩	⟨Ʞq⟩	[Ʞq]			⟨qꞰ⟩
	Voiced (and prenasalised)	/ᶢꞰ͡ɢ/	⟨gꞰq⟩ [ᶰꞰɢ~Ʞɢ]	[Ʞɢ]	([ᶰꞰɢ])			⟨ɢꞰ⟩ [ᶰꞰɢ]
	Aspirated stop	/Ʞ͡qʰ/	⟨Ʞqh⟩	⟨Ʞqʰ⟩	[Ʞqʰ]			⟨qꞰh⟩
	Breathy-voiced	/ᶢꞰ͡ɢʱ/	⟨gꞰqh⟩
	Voiceless fricative	/ᵏꞰ͡χ/	⟨Ʞx⟩	⟨Ʞχ⟩	[Ʞq͡χ]	Ʞx (qg etc.)		⟨qꞰχ⟩					⟨Ʞx⟩(?)
	Voiced fricative (prenasalised)	/ᶢꞰ͡ʁ/	⟨gꞰx⟩ [ᶢꞰ͡χ~ɴᶢꞰ͡ʁ]			gꞰx (dqg etc.)
Ejective contour	Ejective stop	/Ʞ͡qʼ/	⟨Ʞqʼ⟩	[Ʞqʼ]	[Ʞqʼ]			⟨qꞰʼ⟩
	Voiced ejective stop	/ᶢꞰ͡qʼ/	⟨gꞰqʼ⟩
	Ejective fricative	/Ʞ͡χʼ/		⟨Ʞχʼ⟩	[Ʞq͡χʼ]		Ʞkhʼ						⟨Ʞqʼ⟩
	Heterorganic affricate / epiglottalised	/Ʞ͡kxʼ/	⟨Ʞqxʼ⟩			Ʞk (qgʼ etc.) [Ʞᵸ]		⟨qꞰχʼ⟩
	Voiced heterorganic affricate / epiglottalised	/ᶢꞰ͡kxʼ/	⟨gꞰqxʼ⟩			gꞰk (dqgʼ etc.) [ᶢꞰˤ]
Egressive	(Voiceless "spurt"; labial only)	/ʘ↑/												⟨pʼ⟩
		IPA	Taa	Nǁng	ǂʼAmkoe	Juǀʼhoan	Korana	Gǀui	Sandawe	Hadza	Dahalo	Xhosa	Yeyi	Damin

Yeyi also has prenasalised/ŋᶢꞰ/.The original researchers believe that[Ʞʰ]and[Ʞχ]are allophones.

A DoBeS (2008) study of the Western ǃXoo dialect of Taa found several new manners: creaky voiced (the voiced equivalent of glottalised oral), breathy-voiced nasal, prenasalised glottalised (the voiced equivalent of glottalised) and a (pre)voiced ejective. These extra voiced clicks reflect Western ǃXoo morphology, where many nouns form their plural by voicing their initial consonant. DoBeS analyses most Taa clicks as clusters, leaving nine basic manners (marked with asterisks in the table). This comes close to Miller's distinction between simple and contour clicks, shaded light and medium grey in the table.

Phonotactics

Languages of the southern African Khoisan families only permit clicks at the beginning of a word root. However, they also restrict other classes of consonant, such asejectivesandaffricates,to root-initial position. The Bantu languages, Hadza and Sandawe allow clicks within roots.

In some languages, all click consonants within known roots are the same phoneme, as in Hadzacikiringcingca/ǀikiɺiN.ǀiN.ǀa/'pinkie finger', which has threetenuis dental clicks.Other languages are known to have the occasional root with different clicks, as in Xhosaugqwanxa/uᶢ̊ǃʱʷaᵑǁa/'black ironwood', which has a slack-voiced alveolar clickand anasal lateral click.

No natural language allows clicks at the ends of syllables or words, but then no languages with clicks allows many consonants at all in those positions. Similarly, clicks are not found in underlying consonant clusters apart from /Cw/ (and, depending on the analysis, /Cχ/), as languages with clicks do not have other consonant clusters than that. Due to vowelelision,however, there are cases where clicks are pronounced in cross-linguistically common types of consonant clusters, such as Xhosa[sᵑǃɔɓilɛ]Snqobile,fromSinqobile(a name), and[isǁʰɔsa]isXhosa,fromisiXhosa(the Xhosa language).

Like other articulatorily complex consonants, clicks tend to be found inlexical wordsrather than ingrammatical words,but this is only a tendency. InNǁng,for example, there are two sets ofpersonal pronouns,a full one without clicks and a partial set with clicks (ńg'I',á'thou',í'we all',ú'you', vs.nǀǹg'I',gǀà'thou',gǀì'we all',gǀù'you'), as well as other grammatical words with clicks such asǁu'not' andnǀa'with, and'.

The back-vowel constraint

The shape of the tongue in Nama when articulating an alveolar click (blue) and a palatal click (red) [throat to the right]. The articulation of the vowel[i]is slightly forward of the red line, with its peak coinciding with the dip of the blue line.

In several languages, includingNamaandJuǀʼhoan,the alveolar click types[ǃ]and[ǁ]only occur, or preferentially occur, beforeback vowels,whereas the dental and palatal clicks occur before any vowel. The effect is most noticeable with the high front vowel[i].In Nama, for example, the diphthong[əi]is common but[i]is rare after alveolar clicks, whereas the opposite is true after dental and palatal clicks. This is a common effect ofuvularor uvularised consonants on vowels in both click and non-click languages. InTaa,for example, the back-vowel constraint is triggered by both alveolar clicks and uvular stops, but not by palatal clicks or velar stops: sequences such as*/ǃi/and*/qi/are rare to non-existent, whereas sequences such as/ǂi/and/ki/are common. The back-vowel constraint is also triggered by labial clicks, though not by labial stops. Clicks subject to this constraint involve a sharpretractionof the tongue during release.

	Abrupt release	Noisy release
ballistic tongue retraction & back-vowel constraint	ǃ	ǁ,ʘ
no retraction, no constraint	ǂ	ǀ

Miller and colleagues (2003) usedultrasound imagingto show that the rear articulation of the alveolar clicks ([ǃ]) in Nama is substantially different from that of palatal and dental clicks. Specifically, the shape of the body of the tongue in palatal clicks is very similar to that of the vowel[i],and involves the same tongue muscles, so that sequences such as[ǂi]involved a simple and quick transition. The rear articulation of the alveolar clicks, however, is several centimetres further back, and involves a different set of muscles in the uvular region. The part of the tongue required to approach the palate for the vowel[i]is deeply retracted in[ǃ],as it lies at the bottom of the air pocket used to create the vacuum required for click airstream. This makes the transition required for[ǃi]much more complex and the timing more difficult than the shallower and more forward tongue position of the palatal clicks. Consequently,[ǃi]takes 50mslonger to pronounce than[ǂi],the same amount of time required to pronounce[ǃəi].

Languages do not all behave alike. InNǀuu,the simple clicks/ʘ,ǃ,ǁ/trigger the[əi]and[æ]allophones of/i/and/e/,whereas/ǀ,ǂ/do not. All of the affricated contour clicks, such as/ǂ͡χ/,do as well, as do the uvular stops/q,χ/.However, the occlusive contour clicks pattern like the simple clicks, and/ǂ͡q/does not trigger the back-vowel constraint. This is because they involve tongue-root raising rather thantongue-root retractionin the uvular-pharyngeal region. However, inGǀwi,which is otherwise largely similar, both/ǂ͡q/and/ǂ͡χ/trigger the back-vowel constraint (Miller 2009).

Click genesis and click loss

One genetic study concluded that clicks, which occur in the languages of the genetically divergent populations Hadza and!Kung, may be an ancient element of human language.However, this conclusion relies on several dubious assumptions (seeHadza language), and most linguistsassume that clicks, being quite complex consonants, arose relatively late in human history. How they arose is not known, but it is generally assumed that they developed from sequences of non-click consonants, as they are found allophonically fordoubly articulated consonantsin West Africa,for/tk/sequences that overlap at word boundaries in German,and for the sequence/mw/inNdauandTonga.Such developments have also been posited in historical reconstruction. For example, theSandaweword for 'horn',/tɬana/,with a lateral affricate, may be a cognate with the root/ᵑǁaː/found throughout theKhoe family,which has a lateral click. This and other words suggests that at least some Khoe clicks may have formed from consonant clusters when the first vowel of a word was lost; in this instance *[tɬana]> *[tɬna]>[ǁŋa]~[ᵑǁa].

On the other side of the equation, several non-endangered languages in vigorous use demonstrate click loss. For example, theEast Kalahari languageshave lost clicks from a large percentage of their vocabulary, presumably due toBantuinfluence. As a rule, a click is replaced by a consonant with close to themanner of articulationof the click and theplace of articulationof the forward release: alveolar click releases (the[ǃ]family) tend to mutate into a velar stop or affricate, such as[k],[ɡ],[ŋ],[k͡x];palatal clicks ([ǂ]etc.) tend to mutate into a palatal stop such as[c],[ ɟ],[ ɲ],[cʼ],or a post-alveolar affricate[tʃ],[dʒ];and dental clicks ([ǀ]etc.) tend to mutate into an alveolar affricate[ts].

Difficulty

Clicks are often presented as difficult sounds to articulate within words. However, children acquire them readily; a two-year-old, for example, may be able to pronounce a word with a lateral click[ǁ]with no problem, but still be unable to pronounce[s].Lucy Lloydreported that after long contact with the Khoi and San, it was difficult for her to refrain from using clicks when speaking English.

See also

• Bilabial clicks
• Dental clicks
• Alveolar clicks
• Fricated alveolar clicks
• Lateral clicks
• Retroflex clicks
• Palatal clicks
• Back-released click
• Nasal clicks
• Glottalised clicks
• Pulmonic-contour clicks
• Ejective-contour clicks
• Click letters
• List of phonetics topics
• Sublaminal lower alveolar click
• Clicking noise

Bibliography

• Ladefoged, Peter (1968).A phonetic study of West African languages: An auditory-instrumental survey(2nd ed.). Cambridge University Press.ISBN0-521-06963-7.
• Ladefoged, Peter;Maddieson, Ian(1996).The Sounds of the World's Languages.Oxford: Blackwell.ISBN0-631-19815-6.
• Amanda Miller, Levi Namaseb, Khalil Iskarous. 2003.Tongue Body constriction differences in click types.
• Amanda Miller, 2011. "The Representation of Clicks". In Oostendorp et al. eds.,The Blackwell Companion to Phonology.
• Traill, Anthony & Rainer Vossen. 1997.Sound change in the Khoisan languages: new data on click loss and click replacement.J African Languages and Linguistics 18:21–56.

External links

• Collection of click-language links and audio samples.
• Hartmut Traunmüller (2003) "Clicks and the idea of a human protolanguage",Phonum 9:1 – 4 (Umeå University, Dept. of Philosophy and Linguistics)Archived22 July 2012 at theWayback Machine
• Classifying clicks