2.1.1 Morphophonological structure

Although the morphology of !Xóõ is not fully worked out, analyses by Traill (Reference Traill1994), Naumann (Reference Naumann2008) and Kießling (Reference Kießling2008) can be somewhat crudely summarised as follows.

!Xóõ has a very simple word structure. Phonologically, a content word (noun, verb, adjective) has the form C*V{V/CV/C}, i.e. a first mora, which starts with a possibly empty consonant cluster, followed by a vowel (which carries tone and may have several voice qualities), and a second mora, which is either a vowel (again with tone and perhaps nasalised), or a consonant (from a small set) and a vowel, or just a consonant (a nasal, which appears to carry tone in some cases). Function words are typically but not invariably monomoraic; and loanwords and onomatopoeic words may vary from this structure. For the content words, the first mora is the root, and the second mora carries grammatical information, such as concord class. Most words in a sentence have their second mora determined by that of the ‘head noun’; the concord system is fairly complex. In citing words that inflect for concord, Traill uses the notations ‹V JV BV LV› as morphophonological representations of the second mora, as in (1).

1. (1)

   

These words may then be extended with (usually monomoraic) affixes to form longer phonological words; such affixes do not contain clicks. Compound words are also possible, and (at least in the dialect studied by Traill) reduplication of the entire word is a common phenomenon.

2.1.2 Tone

Traill marks four surface tones, which apply to the (bimoraic) word: high 〈á〉, mid-level 〈ā〉, mid-falling 〈â〉 and low 〈à〉. Naumann (Reference Naumann2008) analyses this as two monomoraic tones, high and low, so that Traill's surface tones are represented as HH, LH, HL and LL. This analysis is not completely without problems (Naumann forthcoming), but is mostly successful. There remain some monomoraic words which appear to bear a compound tone. The tones are strongly affected by voice quality, and are extensively modified by the concord system. In this article, I shall use Traill's representations for surface tone when citing forms.

2.1.3 Consonant overview

Table I presents the consonant inventory of !Xóõ in chart form. The columns are labelled by place of articulation; the rows will be referred to by number. This chart presents the largest inventory: firstly, it includes the DoBeS western dialect analysis; secondly, it presents, in the lower half, a large number of ‘consonants’ which are notated as phonetic clusters. I discuss in §3.3 whether these are phonological clusters. In the following sections, I describe the consonants in detail.

Table 1

The consonant inventory of !Xóõ.

2.2.1 Initial non-clicks

This part of the inventory is already quite rich. At the top left of Table I, we have a set of stops with five or six places and five to eight manners, depending on count. Apart from the glottal stop, there are five places of articulation: labial, dental, alveolar, velar, uvular. A typologically unusual feature of !Xóõ is that oral labial stops are marginal: in Traill (Reference Traill1994), almost all the few words starting with labial stops, and all words starting with ‹p›, are loans.

The manners are more or less as written: the voiceless, voiced and aspirated stops (rows 1–3) are familiar from languages with this distinction: voiceless stops have about zero VOT, whereas voiced stops have voice lead, and aspirated stops voice lag. The voiced aspirated stops (row 4) are, however, not like the familiar breathy voiced stops of Indic languages: they have voice lead, which persists into the [z] of ‹dz›; voicing ceases at release. Ejectives (row 5) are also familiar; the voiced ejectives (row 6) have voice lead, followed by an ejective release (so ‹dz’› is rather [ds’]).

The uvular ejective affricates ‹qχ’ ɢχ’› (rows 7–8) might be considered another place or manner; because of their occurrence in clusters, it is convenient to arrange them as manners. They are pronounced as notated, although there is some room for argument about whether they are really velar or uvular – see the discussion in §3.1.

Of the plain nasals (row 10), only ‹m n› occur initially. The glottalised nasals (row 11) are initials, and are nasal stops with an initial glottal check. Amongst the continuants (rows 12–13), ‹s χ› and marginally ‹h› occur initially in native words; the others may occur in loanwords.

Finally, at the bottom left of Table I, there is a group of initials written as phonetic clusters. The pulmonic clusters (rows 22–23) are pronounced as written, with a strong uvular fricative. The ejective clusters (rows 20–21) vary according to dialect and register. Again, the exact place is arguable, and in careful eastern speech, Traill records pronunciations such as [t'q’], although with no instrumental confirmation of a true double ejective. These clusters are rare in the DoBeS data, but reasonably supported by Traill (Reference Traill1994), apart from ‹pqχ’›, which occurs only in the superbly onomatopoeic word ‹pqχ’àli› ‘the sound of a rapid evacuation of the bowels’.

2.2.2 Medial consonants

As remarked in §2.1.1, the bimoraic word may be bisyllabic, with the second syllable starting with one of a very small set of consonants. These are ‹b m n ɲ j l r›. ‹j› in Traill's data varies from [j] to [ɟ]. In Traill, ‹r› occurs only in loanwords; in DoBeS, ‹l› occurs only in loanwords, and ‹r› corresponds to Traill's ‹l› in native words.

2.2.3 Final consonants

The final consonants are ‹m n ŋ p b r›. All but ‹m n› are marginal, occurring in loanwords or onomatopoeic words. According to DoBeS, final ‹m n› are more vocalic than consonantal, carrying a mora and a tone. Traill does not mention this, although it is very obviously the case in his recordings.

2.3.1 Simplex click consonants

The clicks in rows 1–11 of Table I are notated as phonetically simplex consonants. The anterior articulation of these clicks matches their non-click counterparts: for example, ‹ʰ› (row 4) is a palatal click, with voice lead up to the posterior (velar) closure, and aspiration following the posterior release. The voiceless nasal clicks (row 9) such as ‹› have no non-click counterparts. They are pronounced as written: a voiceless ‹ǂ› together with velar lowering around the closure period. This accompaniment will be discussed further in §5.2.

2.3.2 Complex click consonants with long closure

The clicks in rows 14–21 are written with a following [q], which, as noted above, is intended to indicate a significant prolongation of the posterior closure. Thus in ‹›, the click burst is more or less simultaneous with, and so drowns, the posterior release, whereas in ‹q› the posterior release can be heard after the click burst (and seen on spectrograms).

The various modifications – aspiration, ejection, ejective affrication – of the posterior release are pronounced as written.

The voiced consonants, in the odd-numbered rows, are pronounced with voice lead into the posterior closure period, and it is not unusual to hear nasalisation as well, which is probably simply phonetic enhancement of the prevoicing. Voicing stops before the posterior release.

2.3.3 Other complex click consonants

Rows 22–27 contains clicks where the click appears to be (phonetically) followed by another sound. I discuss below whether these are phonological as well as phonetic clusters; here I consider just their phonetics.

The ‹χ› fricative clicks in rows 22–23 are so notated because the fricative is fairly long and prominent, making [χ] more descriptive than the possible alternative [χ], which suggests an affricated posterior release. As I discuss below, there are also systematic reasons for treating them as a click followed by a fricative.

The ‹h› clicks in rows 24–25 have received special attention in the phonetic literature. This, or a similar, ‹h› accompaniment is found in other languages, including Khoekhoe. It has a distinctive auditory impression, as a long crescendo aspiration (around 200 ms, sometimes even 400 ms) can be heard after the click; but the posterior release is not audible. For Khoekhoe (Nama), Ladefoged & Traill (Reference Ladefoged and Traill1984) used airflow measurements to establish that the silent start is achieved by nasal venting during the click [h]; for !Xóõ, Traill (Reference Traill1991) showed that this is supplemented by breathing in during the click (so [ h]), making it the only established example of ingressive pulmonic airflow in normal language. There is a question about whether the nasalisation is phonetic or phonological, which will be touched on below. I treat it as phonetic, and do not represent it.

The clicks ‹ʔ› in rows 26–27, with glottal stop, also tend to have nasalisation, at least in the voiced version, and this may or may not be phonological – here I have assumed not. They are auditorily distinguished from the ejectives ‹’› in rows 5–6 mainly by the lack of an audible posterior release – similar to the difference between [ak'a] and [ak⌝ʔa].

3.3.1 Unitary analyses

Until the 1970s, linguistic descriptions of Khoisan languages recognised the different series of clicks, but did not analyse the accompaniments, which were then called ‘effluxes’ (Beach Reference Beach1938). That work itself is a very thorough (and still useful) study of Khoekhoe, but Beach does not classify or analyse the accompaniments (of which Khoekhoe has only five – ‹ ʰ h ʔ›).

Snyman (Reference Snyman1970) takes the same approach in his study of the Ju language Ju|'hoansi, also called !Xũ. This language has the usual four ‹! | ‖ ǂ› click types, with, according to Snyman, some fourteen accompaniments.Footnote ³ Snyman explicitly presents each such consonant as a phoneme, ascribing SPE-style features to each.

This unitary click analysis has obvious drawbacks, which become more pressing as the number of accompaniments increases. In the case of !Xóõ, it leads to the statement that the language has 83 (attested) distinct click phonemes (per Traill), or 115 (per DoBeS), as in Table I. While few things can be said to be impossible, many people find this to be beyond the limits of what human language might be expected to maintain. There are several reasons for this. For one thing, it poses a considerable challenge to the language acquirer. This is especially so when one considers the rarity of many of the ‘phonemes’. The size of the !Xóõ vocabulary is not known, but Traill (Reference Traill1994) lists about 3000 native words (or rather stems), of which about 2000 contain clicks. Though the true native vocabulary may be rather larger (or may have been before the enforced sedentarisation and migration in the 1980s and 90s), Traill was specifically looking for phonologically illustrative material. Nonetheless, there are three ‘phonemes’ that occur in only one word each – for example, the sound ‹› is supported only by ‹ a› ‘sit or stand close together’ – and thirty that occur in fewer than ten words each, including every member of the ⊙ series. Table II lists the number of words for each click sound recorded in Traill (Reference Traill1994).

Table 2

Click frequencies in the lexicon (Traill Reference Traill1994).

Another indication of the functional load of each phoneme is the incidence of minimal pairs. While there is in general no reason to expect contrasts to be demonstrable between every pair of phonemes, counting the total number of pairwise contrasts gives an indication of the global strength of contrasts. Taking English, for example, with its average-sized consonant inventory, more than 95% of the possible pairwise consonant contrasts are illustrated by minimal pairs, even when one only considers monosyllables.

In !Xóõ, the expected number of minimal pairs is decreased by its very large vowel inventory (as well as the non-click consonants), but increased by the very restricted shape of words: given the basically bimoraic word shape, and the various phonotactic restrictions, there are about 13,000 possible click-initial words in Trail's analysis, ignoring tone, compared to the 36,000 or so possible English monosyllables. It is perhaps remarkable that !Xóõ does have a little more than half of the 3403 unitary minimal pairs; and almost three quarters if one ignores tone.Footnote ⁴ Nonetheless, combined with the rarity of many unitary phonemes, one must wonder how so many distinctions survive.

If we take a more realistic approach, and only ask for each click to contrast with other clicks of the same anterior place (analogous to looking for contrasts among English /t d s θ ð n l r/), the picture is somewhat better, but still surprisingly rarefied: almost 30% of such contrasts are not supported by a minimal pair, even if we ignore tone. In English, all contrasts of manner at a given place are supported by multiple minimal pairs, even for such historically recent contrasts as /θ/ vs. /ð/.

3.3.2 Cluster analysis

Even a cursory glance at Table I invites the suspicion that at least the more complex accompaniments are really clusters. Consider, for example, the click ‹qχ’› (row 20). Given that we see also the free-standing consonant ‹qχ’› (row 7), as well as the non-click ‹pqχ’ tqχ’ ʧlig;qχ’› combinations, also in row 20, the suspicion becomes practically unshakeable. Moreover, as I noted above, all these sounds vary similarly with dialect and register – [qχ’] (or velar [kˣ’] according to Traill) itself is a western dialect pronunciation, whereas the eastern dialect has [k'q] in citation form, with the western form in fast speech (Traill Reference Traill1994: 36).

In Traill (Reference Traill1985), he assumes a unitary analysis, despite its ‘implausibility’, for most of the book, pleading reluctance to violate tradition. However, at the end of the book, he puts forward the above argument, and proposes what I shall call the cluster analysis.

As can be seen from Table I, ‘every one of the simple accompaniments that forms a phonetic cluster with a click (except possibly for delayed aspiration) exists as an independent consonant’ (Traill Reference Traill1985: 209; emphasis in the original). Traill therefore proposes a fairly extensive cluster analysis, in which the basic clicks are [ ], and all the others are viewed as clusters. This obviously simplifies the phoneme inventory dramatically: instead of 17×5=85 click phonemes, there are just 4×5=20, and all the others arise from combinations with phonemes already in the non-click inventory. It also (he asserts) has other nice effects on the phonological analysis, mostly by converting complex ‘featural’ rules into natural coarticulatory consequences of the components of the clusters.

This cluster analysis is not completely unproblematic. Traill mentions a couple of ‘minor details’, such as the awkward absence of free-standing /h/ other than in a couple of interjections; other problems arose later when in Traill (Reference Traill and van Staden1993) he attempts to put !Xóõ in a feature-geometric framework: the durations of some clusters does not match very well with feature-geometric requirements on timing slots. Despite this, the analysis seems compelling to many.

In recent years, the cluster analysis has become quite widely accepted as the natural way to analyse Khoisan languages. I have already mentioned Güldemann's (Reference Güldemann2001) cross-Khoisan analysis, and will discuss it further below.

A recent substantial work discussing cluster analysis at some length is Nakagawa (Reference Nakagawa2006). |Gui is a Khoe language of fairly high click complexity, spoken in Botswana, with the usual four clicks, and thirteen accompaniments, which are a subset of the !Xóõ range. Nakagawa adopts a moderate cluster analysis, based on Traill's proposals. Because, unlike Traill (Reference Traill1985), he recognises plain ejectives (‹’›) and aspirates (‹ʰ›), he includes these as basic clicks, so ending up with 4×6=24 click phonemes, plus 4×7=28 clusters.

Similarly, Naumann's (forthcoming) study of western !Xóõ also adopts a Traillian analysis, largely following and extending the moderate cluster analysis – my terms ‘simplex’ and ‘complex’ in §2.3 are chosen to match with the DoBeS view that rows 1–13 of Table I are phonemes, and rows 14–27 clusters. As well as the arguments involving parsimony and symmetry of systems, and on the grounds of the phonetic properties that I sketched in §2.3, Naumann also gives some informal observations of speaker behaviour that seem to support the cluster analysis: for example, his informants sometimes described ‹!qʰ-› words as starting with ‹!›. Under the moderate cluster analysis, the phonemes are those in (6).

1. (6)

   

3.3.3 Güldemann's analysis

The cross-Khoisan analysis of Güldemann (Reference Güldemann2001) is quite radical from the point of view of phonological theory. Some of its roots lie in Traill's discussions of early notions of subsegmental structure, but Güldemann goes further. As sketched above, he uses a hierarchical structure, so that segments can combine to make bigger segments. One of his main aims is to integrate the click and non-click systems, so there is a top-level featural distinction [suction] (following SPE) distinguishing clicks, and then below that a hierarchy of features/subsegments. For him, ‘simple’ stops are the voiced and voiceless stops/clicks. Simple stops can be modulated by aspiration and glottalisation (ejectivity is treated as glottalisation for phonological reasons, such as the constraint in (2b)), to produce ‘complex’ stops. Either simple or complex stops can then be sequentially combined with other stops to form ‘cluster’ stops – which are both clusters and single segments with their own featural description.

Güldemann's discussion brings in a number of aspects of cross-Khoisan phonology, but a detailed review would take more space than is justified for the purposes of this article. Suffice it to make three observations. Firstly, he remains unable to settle firmly on the appropriate set of place features for clicks, because of some of the issues mentioned above in §3.2. Secondly, for him the !Xóõ alveolar affricate series (‹ʧlig;›, etc.) is indeed phonologically affricated, whereas Traill treats it (as I do implicitly) as an incidentally affricated series of alveolar stops. Finally, it is not entirely clear how this approach is to be integrated into formal phonological theories, whether rule- or constraint-based.

3.3.4 The radical cluster analysis

Nakagawa (Reference Nakagawa2006: §5.3.1.3), a section in which he considers a radical cluster analysis, requires special mention in the context of this article. The radical cluster analysis is ‘radical’ in that it proposes that there is only one click phoneme at each place – which, as will be seen, is precisely the argument this article makes about Khoisan. However, Nakagawa sets up the radical cluster analysis as a straw man to justify his preferred analysis – it is germane, therefore, to explain why he argues that the radical cluster analysis fails. I will go on to argue, as the proposal of this paper, that it is in fact correct to propose such a radical analysis, but a conceptual change in the nature of phoneme and segment is required for it to work as desired.

The difficulty Nakagawa has is choosing which click is basic. An obvious first thought would surely be that the plain unvoiced click is the basic click. However, Nakagawa finds this untenable, because although |Gui has the voiced nasal click [] (but not []), it does not have a plain velar nasal [ŋ] in its inventory with which ‹› could cluster. He concludes, therefore, that the only viable choice for the unit click in radical cluster analysis is the nasal click, with some phonetic rules to explain how it combines with other phonemes to form the other clicks – rules that have to be inelegantly restricted in their application, to avoid destroying the non-click inventory.

As a reviewer observes, it is questionable whether Nakagawa's reasons are sufficient; ‹ŋ› could simply have a defective distribution, or possibly the nasal that combines with clicks is ‹n› (which is compatible with my formulation below in which click accompaniments are not specified as velar or back). However, I claim that while the radical cluster analysis is correct, a change to parallel clustering brings a number of improvements.

3.3.5 Arguments against the cluster analysis

Although Naumann (forthcoming) adopts the cluster analysis, he also finds some evidence weighing against it. Firstly, it is surprising that the A-Raising Rule (5) still operates following clusters with uvular stops – one would expect a uvular to block any raising effect of the previous click. Secondly, he conducted an informal onset-dropping experiment: two speakers were trained to drop the first sound of words in Afrikaans, and then asked to do the same with !Xóõ words. Neither speaker simply dropped the click from the cluster; either they dropped the entire cluster or they produced words starting with ‹h› or ‹ʔ›. My proposal will resolve both these issues (see §5.1).

Amanda Miller, whose study of Ju|'hoan was mentioned earlier (Miller-Ockhuizen Reference Miller-Ockhuizen2003), has recently been working with a number of colleagues on the almost extinct language N|u. Although in that work she follows a cluster analysis, Miller et al. (Reference Miller, Brugmann, Sands, Namaseb, Exter and Collins2009) argue that cluster analyses are wrong. Instead, they propose to extend the range of features by which clicks are classified, and in particular to add contour values for the airstream feature. These are to simple airstream values as affricates are to stops and fricatives. N|u has a mid-sized range of accompaniments, which, adapting Miller et al.'s notation to ours, are ‹ ʰ ʔ ʰ q qʰ χ χ’›. (N|u ‹ʰ› does not appear to have such a markedly long crescendo aspiration as !Xóõ [h]. The ‹χ’› is probably what I represent as ‹qχ’›.)

The way that Miller et al. classify these clicks by ‘airstream mechanism’ is as follows: (i) the simple and nasal clicks ‹ ʰ ʔ ʰ › are said to have just a lingual airstream; (ii) the clicks ‹q qʰ χ› are said to have a ‘linguo-pulmonic’ airstream, reflecting their status (as in the similarly notated !Xóõ clicks) as moving from a click into a normal pulmonic release, with a clearly audible [q qʰ χ]; (iii) similarly, the click ‹χ’› is said to have a ‘linguo-glottalic’ airstream.

From the phonetic point of view, this classification allows us to add the click consonants to the standard IPA chart by extending it with new sections for the different values of airstream feature. So we have a block of pulmonic consonants, followed by a block of lingual consonants, followed by a block of linguo-pulmonic, and so on. A concrete motivation for this concerns the difference between ‹› and ‹q›, a distinction shared by !Xóõ and N|u. As discussed in §3.1, Miller et al. consider (and I agree) that there is no role for velar/uvular place in the contrast; therefore there is only a timing difference, and this is best seen as a contoured airstream.

From our perspective, this is still a unitary analysis, but with different feature values for the various accompaniments; it does not change the number or identity of phonemes in the unitary analysis.

Miller's more phonological arguments for this analysis are laid out in Miller (Reference Miller, van Oostendorp, Ewen, Hume and Rice2011). Two of the major arguments are the difficulty of decomposing all clicks into segments that also appear independently (as noted by Nakagawa; see above) and the fact that typologically every language that allows obstruent–obstruent clusters also allows obstruent–sonorant clusters, whereas there are none of the latter in Khoisan languages. My proposal will address both these points (see §6.2).

4.1.1 Concurrent clicks in !Xóõ

If we apply this idea to the !Xóõ click inventory (I call this the concurrent analysis), we obtain a dramatic simplification and reduction. The five clicks become phonemes in their own right; and we can now reinterpret our phonetic meta-notation for accompaniments, such as ‹q›, in which the ‹› is really a variable ranging over the five click symbols, into a true phonetic and phonemic notation, in which ‹› is not a variable, but a novel phonetic symbol to indicate the point at which this sequence of segments synchronises with any concurrent click segment. The phonetic output now follows from common phonetic rules: ‹!q› is phonemically ‹(!⊗q)›, and an unexceptional phonetic rule unifies the posterior closure required by the click with that required by [q], resulting in a long uvular stop with a click at the beginning.

Thus, even if we retain all 23 unitary accompaniments, the click-inventory size is now 5+23 instead of 5×23, as set out in (7). Instead of an exceptionally large array of consonants, we have a modest set, with the formerly apparent complexity being simply clustering. Apart from the fact that the clustering is concurrent rather than sequential, it is no more exceptional than, say, clusters in Russian.

1. (7)

   

Moreover, all the arguments for a sequential cluster analysis within accompaniments hold just as well in this setting as they do in the traditional setting. The moderate cluster analysis, for example, naturally becomes what might be called a concurrent moderate cluster analysis. Now there are five clicks and eight accompaniments, as in (8), and all the rest is clustering, both concurrent and sequential: for example, the click ‹qχ’› can be analysed as /(!⊗qχ’)/. In this analysis, !Xóõ has only thirteen click phonemes. For good measure, the arguments against clustering outlined at the start of §3.3.5 no longer obtain: since the ‘onset’ of a word is now a concurrent cluster, it is not surprising that speakers had difficulty deciding how to drop it; and we shall see soon how the failure of uvulars to block A-Raising emerges naturally.

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If one adopts Miller's proposal (§3.3.5), which is a unitary analysis, one can still adopt the concurrent analysis: at the phonological level, ‹q› will be an accompaniment with a linguo-pulmonic airstream, which then combines with a phonological pure click to produce her phonetic ‘linguo-pulmonic’ consonant.

4.1.2 A formal implementation

I intend this proposal as one of basic linguistic theory (Dixon Reference Dixon1997), since it can be understood in any framework, formal or informal, that supports the notions of phoneme and segment. To demonstrate a precise implementation, I give a version in a variant of SPE. I shall use unspecified features in phonemes, rather than go down the formal route of SPE markedness theory – it is a routine but unenlightening exercise to recast everything in strict SPE. I use SPE notation for rules; unspecified features are written as e.g. [∅voice].

For theories such as Optimality Theory (Prince & Smolensky Reference Prince and Smolensky1993) which also use a feature-based phonemic representation, it is similarly straightforward to add concurrency; and all the rules I consider can be readily translated to ranked constraints.

Recall that in SPE there is a set of binary features, underlying representations (URs) are strings of feature bundles, which may be unspecified for some features, and the output of the rewriting rules is a string of fully specified feature bundles. Despite Chomsky & Halle's express discouragement of such terminology, one can say that ‘phoneme’ corresponds to a feature bundle in the UR, and ‘segment’ to a bundle in the output, and I will adopt this henceforth. I assume that features for clicks are as in (14)–(17) below, so that clicks share a feature [+lingual], and all the usual non-click phonemes are specified [–lingual]. The first step is to extend the strings in the URs, as in (9).

1. (9)

   

Note that I will use parentheses with the usual mathematical meaning of grouping. This is potentially confusable with the SPE use of parentheses to indicate optional elements in rules, but in practice it will always be clear from context which meaning a given parenthesis has.

Definition (9) by itself allows arbitrary combinations; as concurrency is intended to reflect the physical possibility of combining different sounds, I impose (10).

1. (10)

   

The effect of (10) is to forbid clicks and non-clicks to combine within one half of a concurrent composition. For the moment, I also stipulate (11).

1. (11)

   

(11) further restricts ⊗ to combining clicks on one side with non-clicks on the other. I now define the click phonemes.

1. (12)

   

This is the definition that turns our accompaniment notation ‹› into a symbol for an actual phoneme. Now / ʰ/, etc. are genuine phonemes in the inventory, albeit with the unusual phonotactic constraint (which can be dispensed with, at least formally – see §6.1) that they occur only in concurrent clusters. This constraint is formulated as (13).

1. (13)

   

This constraint forbids pure clicks and pure accompaniments from appearing by themselves in URs.

(14)–(17) sets out the featural specifications I assume in the discussion following, both for the click phonemes and for the other phonemes of !Xóõ. Some choices are of course a little arbitrary; others are justified in the following sections.

The pure clicks /⊙ | ! ‖ ǂ/ are specified for [+consonantal, –vocalic, –continuant, +lingual], together with the features in (14).

1. (14)

   

The pure accompaniments are specified for the features in (15).

1. (15)

   

Manner features for the pulmonic stops are specified as for the accompaniments, using [voice], [spread glottis] and [glottal closure], together with [+delayed release] for the alveolar affricated stops and the uvular ejective affricates /qχ’ ɢχ’/. Place features are as in SPE, with one exception: we distinguish dentals /t d …/ from alveolars by [high] (motivated largely by the raising behaviour of dentals described in §5.1), as in (16).

1. (16)

   

Continuants, glides, liquids and nasals are as in SPE; I tentatively consider the glottalised nasals to be clusters: /ʔm ʔn/.

Vowels are standard, except that /a/ is unspecified for [back], as in (17).

1. (17)

   

Creaky vowels are [+glottal closure], breathy vowels are [+spread glottis], pharyngealised vowels are [+pharyngeal] and strident vowels are [+pharyngeal, +spread glottis].

Now the ‘simplex’ !Xóõ clicks have underlying representations such as /(!⊗ʰ)/. The question remains of the ‘complex’ clicks. As I discuss later, there is room for manoeuvre here. For the moment, I assert that ‹!qʰ›, for example, has the UR /(!⊗qʰ)/: that is, it is a concurrent cluster, one half being the pure click, and the other being a sequence of ‹› and ‹qʰ›, as shown in (18) for the alveolar clicks.

1. (18)

   

To complete the formalisation, I need to consider whether concurrency survives to the output stage of the SPE rewriting process. One may have different views on this, according to where one prefers to draw the phonology/phonetics boundary. My preferred approach is to leave the click concurrency in the output, but to resolve the complex clustering, by adding rule (19) late in the SPE rule chain.

1. (19)

   

This is SPE notation for ‘a [+lingual] phoneme docks on to a lingually unspecified phoneme in the other concurrent half’. For example, /(!⊗qʰ)/→[(!⊗)qʰ] by this rule, with 1=/!/, 2 empty, 3=//, 4=/qʰ/.Footnote ⁵

(19) is one of several variations on the technical devices that could be employed to achieve the effect of synchronising clicks with the pulmonic airstream sounds; this one is natural because of the intuition it gives for // being a manner-carrying placeholder waiting to receive a click.

One might wish to eliminate the idea of concurrent segments from the output. This can be done by adding a later rule, (20).

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The ⊔ operation is not standard SPE notation, but has been recently suggested as a useful addition by Bale et al. (Reference Bale, Papillon and Reiss2013); the rule can of course be written out in standard notation, but is lengthy. The result of applying this rule to /(!⊗)qʰ/ is the purely sequential cluster [qʰ], where [] has all its features specified.

5.1.1 Moderate A-Raising

Recall that the first part of the A-Raising Rule (5a) raises ‹a› to [ɛ] before ‹i›, ‹Ci› or a nasal, and after a dental non-click or a dental or palatal click. This rule applies even in a word like ‹|q'àn-tà› [|q'n-tà] ‘small (pl)’, showing that the rule targets the click rather than the accompaniment: the apparently intervening uvular, which one would normally expect to block a phonetic raising effect, does not do so. In the formal presentations that follow, I shall mostly omit the raising after dental non-clicks; this is merely to simplify the notation.

This rule provides the evidence for how we should distribute concurrent and sequential clustering. A priori, it is possible that ‹|q'án› could start with /(|⊗q')/ or with /(|⊗)q'/. Indeed, one could even analyse ‹|q'án› as /(|⊗q'án)/, and since Khoisan languages allow only one click per stem, this would make some sense from an autosegmental viewpoint. On the other hand, considerations of simplicity and economy suggest that (⊗) should be applied with the smallest scope, so that all of each half is genuinely concurrent with all of the other half, so favouring /(|⊗)q'/. However, the behaviour of the A-Raising Rule suggests that /(|⊗q')/ is correct.

For the moment, I ignore the question of what it is that the triggering click types have in common, and just list them in rule (24).Footnote ⁹

1. (24)

   

Formally, there is little difference between this and the equivalent rule in a standard cluster analysis, where the click context would be expressed as the class of dental and palatal simplex clicks followed by C₀, instead of a concurrent cluster of the two pure clicks with the accompaniments. Assuming all the constraints and rules in §4.1.1, it can be shown that any set of constraints and rules in this concurrent formalism can be translated into a standard set that will produce the same output; I am adding not expressive power, but naturalness. Here, we avoid the rather peculiar situation in sequential analyses of the raising power of the clicks passing through uvular stops (which one expects to be strongly lowering), because here the target vowel is immediately adjacent to both the click and the accompaniment.

The transparency of the /C/ in /-Ci/ requires a little comment – why is it transparent to the raising power of ‹-i›, while (I claim) a sequential uvular should block the licensing from the [+high] clicks? One could invoke theories that account for VV interactions as long-distance (e.g. Germanic umlaut), while requiring strict adjacency for CV interactions (e.g. English palatalisation). However, there is a simpler argument: the only permissible Cs are /b m n ɲ j l r/, all of which are either [+high] or do not involve the tongue at all – and the nasals cause raising in any case.Footnote ¹⁰

5.1.2 Full A-Raising

The rules become more interesting when we consider Traill's account of the Back Vowel Constraint in eastern !Xóõ and the exceptions to it. Recall that his version of the Back Vowel Constraint (4) forbids front vowels after any back consonant, including all clicks – arguing that since clicks involve a velar/uvular closure, they are surely at least as back as ‹k›. One exception involves just ‹k›: there is a grammatical particle ‹kV›, which appears as ‹ke ki› in some concords. Traill notes that ‹ke ki› are often pronounced instead as ‹te ti›, so obeying the constraint phonetically. The other class of exceptions involves the clicks ‹| ǂ›, where phonetic front vowels do appear, for example in ‹ǂíi› ‘steenbok’ and ‹|îi› ‘to be’. Traill accounts for most of these by asserting that they are underlyingly, e.g. ‹ǂái›, with both parts of the A-Raising Rule (5) applying to change ‹a› to ‹i›. The evidence for this is partly internal: the plural of ‹ǂìi› is ‹ǂábaté›, with the morphology in (25).

1. (25)

   

where ‹-té› is the current productive pluraliser. There is also cross-dialectal evidence: for example, in the DoBeS data, ‘steenbok’ is ‹ǂâi›, pronounced [ǂi], with moderate A-Raising. Indeed, although Traill abandons ‹|îi› ‘to be’ as an unexplained exception, a referee points out that DoBeS has what may be the same verb ‹|âi› ‘stay, be at a place’, so even that can be accounted for.

I have not so far given a precise specification of the preceding context in full A-Raising. Traill (Reference Traill1985: 70, Reference Traill1994: 40) is not explicit about whether it is triggered by any dental or palatal click, or just some of them, for example the plain clicks. However, in his dictionary (Reference Traill1994) he marks fully raising words: e.g. ‹ǂíi› is entered as 〈ǂái (> [ǂíi])〉. Thus one can see which posited underlying ‹ ai› words undergo full A-Raising. For example, ‹|χāi› ‘bowstring hemp plant’, which is also a class 1 noun, with plural ‹|χāba-té›, is entered just as 〈|xāi〉. Indeed, a recording of it is available, and it is pronounced with moderate raising.Footnote ¹¹ An examination of all the data shows (26).

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That is, although a uvular segment in the accompaniment does not block moderate A-Raising, it does block full A-Raising. In SPE, uvulars are contrastively specified for [+back] and [–high], so there is a choice of which feature to use in the rule. I will accept Traill's view that A-Raising is indeed raising rather than fronting, and employ [high]. So, using the fact that my pure accompaniment phonemes and the two glottal phonemes are unspecified for [high], we can formulate the full A-Raising rule as (27).

1. (27)

   

Now consider what distinguishes ‹| ǂ› from the other clicks. There have been several suggestions for features that do so. I tend to prefer Traill's notion that the difference is that they leave the tongue blade in a high front position, whereas the others pull the tongue lower and backer, which suggests either [back] or [high], or perhaps both. The rules work nicely if both are specified, as I laid out without explanation in (17).Footnote ¹² Miller uses [pharyngeal] – see below.

Given this, the following rule suggests itself as a combined description of A-Raising before ‹i›.

1. (28)

   

This rule does not explicitly describe the concomitant fronting that results in [i] rather than [ɨ] in the full case – as a referee suggests, it is probably simplest to assume that a later rule fills in [–back]. It is also of course possible to incorporate fronting in (28), as in (27), at the price of some additional inelegance.

This rule neatly shows the concept that the raising and fronting effect of the following ‹i› is moderated either by the click or by the accompaniment. Moreover, since in (16) I used [±high] to distinguish dentals from alveolars, this rule also captures A-Raising with initial dental non-clicks: a non-click initial matches the context by taking the optional lower half to be empty; α then matches against the initial.

Several similarly complex sets of interactions between different coronal consonants and vowel backness are studied by Flemming (Reference Flemming2003), with similar arguments about the different behaviour of the tongue body. The above description can also, as I noted, be cast in terms of fronting rather than raising, and would mostly fit in to Flemming's (Reference Flemming2003) framework.

As examples of the formal application, consider (29).

1. (29)

   

Note that (28) does not agree with Traill's A-Raising Rule (5), because (28) predicts that there should be moderate raising following a ‘back’ click without a uvular accompaniment (whereas in (5) only the ‘front’ clicks trigger any raising). Traill (Reference Traill1994) in fact states that in such contexts ‹a› undergoes mild raising, to [æ]. However, I have studied his available recordings, and in the readings, all ‹-ai› words with back clicks appear to show the same degree of raising as other cases of moderate raising. There is not enough data to make any statistically meaningful claim, but both auditory impression and acoustic measurements suggest this. For example, in one recording ‹!hai› appears to show considerable assimilation, varying from [əi] to [ɛi] in the same speaker.Footnote ¹³ (On phonetic grounds, one might expect raising to be particularly marked in ‹h›, since the long [h] allows plenty of time for the tongue to move away from the position forced by the click. However, there is not enough data available to me to check this.)

It is of course simple to force (29) to match (5), but this requires removing the symmetry between click and accompaniment features, and since the symmetric version appears to be more accurate, there is no call to do so.

5.1.3 The Back Vowel Constraint

Though the underlying ‹a› in most full A-Raising words is adequately supported by other evidence, part of its motivation is to explain exceptions to Traill's phonological Back Vowel Constraint in (4), which prohibits front vowels after any back consonant. As I noted, there is an alternative formulation (3) of the general Khoisan Back Vowel Constraint, which recognises the distinction between the front and back clicks, and it is perhaps unclear why one should recognise this difference in the A-Raising Rule but not in the Back Vowel Constraint.

A similar situation with regard to the Back Vowel Constraint occurs in Ju|'hoan, where front vowels also occur after the front clicks. Unlike Traill, Miller-Ockhuizen (Reference Miller-Ockhuizen2003) does not try to explain this away by a phonetic rule operating after the constraint, but rather states the Back Vowel Constraint in the form in (3), which distinguishes the front ‹| ǂ› clicks from the back ‹! ‖› clicks. Her technique is to assign the feature [+pharyngeal] to ‹! ‖›, and use that in the statement of the Back Vowel Constraint. This use of [pharyngeal] is motivated by the other ‘guttural’ constraints she analyses, but many of these do not appear to apply in !Xóõ. The phonetic grounding of this feature is supported by ultrasound; impressionistically, it seems to me to be a consequence of the apical articulation of ‹! ‖› rather than a primary feature. Miller-Ockhuizen discusses in detail both her own and others' work on the acoustic and articulatory properties of the various clicks, and there are a number of ways in which the front clicks can be seen to differ from the back clicks.

In my approach, the choice made above to specify back clicks as [+back, –high] can be exploited to state the Back Vowel Constraint in a more refined form.

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This makes fully A-Raised words licit at the phonological level, and so removes the notion that they are exceptions. It therefore also allows the few remaining unexplained exceptions, such as ‹|īi› ‘if’, and a dozen or so words in ‹-e-› following a dental or palatal click.

It also permits a front vowel to follow a click with an uvular accompaniment, because both the click and the accompaniment immediately precede the vowel; in a non-concurrent formulation the uvular would block the licensing from the front click. According to Traill (Reference Traill1994), there are indeed a couple of such words: ‹|q'íi-sá ǂɢẽ›.

6.1.1 Accompaniments as pulmonic stops

One might simply say that ‹› is just ‹q› (or ‹k›). This is essentially the radical cluster analysis, made concurrent instead of sequential: the accompaniments are the existing series of uvular (or velar if preferred) stops. It has the same distributional problem as the radical cluster analysis: there is no ‹ɴ›. (There is also no ‹ɴ̥›, but that is not a problem if we follow §5.2.) There is a rather marginal ‹ŋ›, but not in onset position. Either of the solutions suggested for the radical cluster analysis could be applied.

Although this proposal avoids the unusual phonotactic constraint that accompaniments must appear with clicks, it introduces others: for example, why is it that there are no initial clusters ‹qx qh qʔ›? One has to argue that the point of the click clusters ‹x h ʔ› is that the posterior release is inaudible, and that an initial ‹q› with no release is rather pointless, but then the phonotactics must distinguish ‹q› qua accompaniment from ‹q› qua independent consonant.

A major drawback to this approach is that the bare accompaniment now has values for height, backness and linguality, and so all the rules have to be recast in a less elegant form. In particular, if ‹› is just ‹q›, there's nothing to distinguish the two ‹q›s in ‹qq›, and so the synchronisation rule, which previously could identify ‹›, must instead be written to dock the click onto the first uvular segment in the accompaniment. This happens to work, because there is no ‹q›, but it is not elegant.

6.1.2 Accompaniments as clicks

An alternative suggestion is that solitary ‹› is ‹!›. On this view, the accompaniment carries with it a ‘default’ click, which I have somewhat arbitrarily chosen to be ‹!›, but this can be changed by concurrent composition with a different pure click. In the implementation of §4.1.1, this would be done by leaving the ‹› phonemes as they are, and adding a rule that fills in the ‹!› features for an isolated accompaniment.

In such a setting, of course, the chosen default pure click becomes redundant, and can be omitted from the inventory. This solution solves some problems, but there are, to my knowledge, no phonetic or phonological grounds for treating one click as more fundamental than another; and more importantly, it complicates the statement of rules such as A-Raising and the Back Vowel Constraint, as they apply to the default click too.

6.1.3 The place of voice

Another possible, and more substantial, variation has been proposed by Daniel Currie Hall (personal communication). I have chosen to attach all laryngeal features to the accompaniment. Hall notes that [voice] varies orthogonally to all other features, whereas [spread glottis, glottal closure, nasal] are mutually exclusive (assuming the cluster analysis of ‹?›). Why not, then, place [voice] with the clicks rather than with the accompaniment? This would give the basic phonemes /! …/ and accompaniments / ʰ ’ /.

Such an organisation is also used by Güldemann (Reference Güldemann2001) in his feature-geometric approach. Hall suggests the advantages in (32).

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This has obvious merits, similar to those that motivated Güldemann's (Reference Güldemann2001) similar decision. The counterarguments invoke the conceptual basis of the proposal in this article. Ad (a), plain and voiced clicks require just as much synchronisation of separate airstreams as other clicks, and at least in my own experience, voicing clicks is no easier than aspirating them. A click on its own would demonstrate a failure of synchronisation. Ad (b), if there is no sequential clustering, then one must resort to phonetic rules to explain why the clusters with stops have a prolonged closure after the click rather than before or around it. Ad (c), the non-occurrence of ejective, aspirated or nasal clicks in clusters is discussed in the following section.

There is also a more drastic approach to voice, which deserves mention. As is clear from Table I, the voicing distinction pervades the stop system; and as discussed in §2.2–§2.3, it appears as distinct prevoicing in most cases, other than the simple voiced stops. It is therefore tempting to follow the orthographies, and replace the voiced accompaniments ‹ ɢ …› by sequential clusters with a voiced stop: ‹ɢ ɢq …›. To the best of my knowledge, there is nothing in !Xóõ phonology to argue against this, although it goes against almost all phonological tradition.