Vowel quality alternation in Dinka verb derivation: The Agar variety

2.1 Verb shapes

A verb in Dinka is generally a monosyllable which conforms to the segmental shape C(w)(j)V(V(V))C with optional segments in parentheses. Thus, the verb segmentally consists of an onset consonant (C), optionally followed by one or two glides (/w/ and/or /j/ in that order), a vowel which is either short (V), medium (VV) or long (VVV), and a coda consonant (C). ^[2] The voice quality of the vowel is either breathy (◌̤) or non-breathy (◌̰), and the vowel carries a tone which in the Agar dialect is either low (◌̀), high (◌́) or falling (◌̂). ^[3] In my transcription, the voice quality and tone diacritics are placed on the first of a sequence of vowel symbols. ^[4] The monosyllable may be followed by a suffix with the segmental shape -(C)V.

2.2 Derivational and inflectional categories

2.3 Classes of transitive verbal roots

Transitive verbal roots in the Agar dialect fall into four inflectional classes in terms of (i) the vowel length of the inflectionally unmarked (infl. unm.) form of the simple verb and (ii) the tone of the non-finite form of the simple verb (Andersen 1992‒1994: 22–25). Thus, as exemplified in Table 1, a root has either a short vowel and a falling tone (Class 1F), a short vowel and a low tone (Class 1L), a medium-length vowel and a falling tone (Class 2F), or a medium-length vowel and a high tone (Class 2H). The class names given here consist of a number, which indicates the number of morae (1 or 2) in the inflectionally unmarked form, and a letter, which indicates the tone (F for falling, L for low, and H for high) in the non-finite form. As also illustrated in Table 1, all of the four classes contain both non-breathy roots and breathy roots. These classes also determine the way in which derived verbs are formed.

Table 2 gives information about the empirical basis of the description. Thus, this table shows for each of the four root classes how many roots have been examined for each of the six derivational categories. Not all the verbs have been examined exhaustively, i.e. with elicitation of all inflected forms, apart from the inflectionally unmarked form and the non-finite form.

2.4 Voice quality alternation

As summarized in Table 3, voice quality alternation is one of the exponents of derivational categories (Andersen 1992‒1994: 33). In this table, “breathy” means that the derivational category is characterized by breathy voice quality in the root vowel, and thus may involve a shift from non-breathy voice to breathy voice, whereas “inherent” means that no voice quality shift takes place. As seen in the table, centripetal, dative and dativized antipassive verbs have breathy voice. To a large extent, this feature also characterizes antipassive verbs, but with some systematic exceptions in terms of the inflectional class of the root and the inflectional category.

2.5 Vowel gradation system of simple transitive verbs

In Andersen (1993) it was shown how vowel quality alternation works in the inflection of simple transitive verbs. The account uncovered a vowel gradation system with three vowel grades across basic vowel qualities (“series”). A slightly revised version of this system is shown in Table 4 (based on Table X in Andersen [1993: 19]) without regard to vowel length. ^[15]

For each root there is a basic vowel quality, called grade 1 (1°), and for each grade 1 vowel the table shows the two other grades, called grade 2 (2°) and grade 3 (3°). The upper part of the table shows non-breathy vowels, the lower part shows breathy vowels. Moreover, a distinction is made between grade 1 vowels in three different phonological contexts: vowels that are not preceded by a postconsonantal glide (on the left), vowels that are preceded by a postconsonantal /j/ (in the middle), and vowels that are preceded by a postconsonantal /w/ (on the right). Grade 2 differs from grade 1 in that the low central vowel quality /a/ is fronted and raised to lower-mid /ɛ/ in accordance with a morphophonological rule called Fronting (Andersen 1993: 21–25). ^[16] Grade 3 differs from grade 1 in that other vowel qualities than /a/ are lowered in accordance with a morphophonological rule called Lowering (Andersen 1993: 25–32), a process which sometimes involves “breaking” which adds a postconsonantal glide. It should be noted that /ɛ/ is not a basic vowel quality, since it is not a member of the grade 1 inventory; it arises either from fronting of /a/ or from lowering of /e/ or /i/.

The situation delineated in Table 4 is somewhat simplified. Thus, the table disregards that grade 1 of the /a̤/-series has an /ɔ̤/ alternant, cf. Section 4.4 below. It also disregards that some of the vowels have raised variants, cf. Section 4.3 below. Moreover, the table disregards that the contrast between the qualities /a/ and /ɛ/ which exists in medium and long vowels seems to be absent in short vowels (Andersen 1993: 13–14), in which case I use the symbol /a/ to the exclusion of /ɛ/. This means that grade 2 of the various /a/-series appears as /a/ rather than /ɛ/ in short vowels.

Each of the 11 forms of a simple transitive verb “has” (or “belongs to” or “occurs in”) a particular grade. Thus, grade 1, in addition to occurring in the inflectionally unmarked form, is an exponent of 2SG, 1PL, 3PL, PASS and NF. Grade 2 is an exponent of NTS, 3SG and PASS.CT. And grade 3 is an exponent of 1SG and 2PL. Examples are given in Sections 3 and 4 below. The vowel gradation system shown in Table 4 also plays a significant role in the morphology of nouns (Andersen 2002, 2014).

The rest of this article deals with the nature and role of vowel quality alternation in derived verbs with a transitive root, thus complementing the description of the morphology of transitive roots given in Andersen (1992‒1994) and Andersen (1993). First, it is shown that the vowel grade system set up to account for vowel quality alternation in simple verbs also works for derived verbs, but that the distribution of the grades is different and that the phonological range of Fronting is extended. Second, it is shown that the shift from non-breathy voice to breathy voice, which occurs in some derived verbs, involves some systematic shifts in vowel quality as well.

3.1 Distribution of vowel grades in derived verbs

In general, the vowel qualities used in derived verbs are the same as those used in the corresponding simple verbs, but the distribution of the alternants is partly different. This can be seen in Tables 5 and 6, which show all forms with the inherently breathy roots ɡṳ̀t ʻstab’ and t̪à̤r ʻspear’, respectively. ^[17] Both of these roots belong to Class 1 F. Since the root ɡṳ̀t in Table 5 has the grade 1 quality /u/, its grade 2 quality is phonologically identical to its grade 1 quality, while its grade 3 quality is /wo/, cf. Table 4 above. Conversely, since the root t̪à̤r in Table 6 has the grade 1 quality /a/, its grade 3 quality is phonologically identical to grade 1, while its grade 2 quality is /ɛ/.

Based on the forms in Tables 5 and 6 taken together, and on antipassive forms dealt with in Section 3.2 below, the distribution of the vowel grades can be determined as being what is shown in Table 7. The distribution in transitive derived verbs is the same in all four root classes, cf. Tables 10–13 at the end of this subsection. But in antipassive verbs the distribution depends on the root class, as also shown in Table 7.

In derived transitive (i.e., non-antipassive) verbs, as seen in Table 7, the vowel grade is either 2° or 3°, never 1°. The inflectionally unmarked form of such verbs has grade 2, and this is also the grade of NTS, 2SG in centripetal verbs, 3SG, 1PL, 3PL, PASS and PASS.CT. Grade 3 is found in NF, 1SG, 2SG (except in centripetal verbs) and 2PL. Thus, grade 2 here characterizes all the inflectional categories that have either grade 1 or grade 2 in simple verbs, except for NF. Hence, in derived transitive verbs, grade 2 appears to be the default grade and can therefore be taken to be an exponent of the derived status of the verb rather than a means of inflection. Grade 3, by contrast, must be taken to be a means of inflection, namely an exponent of NF, 1SG, 2SG (except in centripetal verbs) and 2PL.

Although the generalizations expressed in Table 7 are based on breathy roots, they also cover non-breathy roots. But here the situation is complicated by the fact that some derived categories exhibit voice quality shift, and for some non-breathy vowels the shift to breathy voice is accompanied by a change in vowel quality, as described in Section 4 below. In general, however, the vowel quality alternation in verbs with their inherently non-breathy voice shifted to breathy voice is the same as in verbs with inherently breathy voice, cf. Table 4 above. This situation is exemplified in Tables 8 and 9, while exceptions are dealt with in Section 4 below. Table 8 shows all forms with the non-breathy Class 2F root mḭ̀it ʻpull’, for which grade 2 is identical to grade 1. Table 9 shows all forms with the non-breathy Class 1F root bà̰r ʻtake along’, for which grade 3 is identical to grade 1. In Table 8 the breathy grade 2 vowel /i̤/ behaves like an /i̤/ in an inherently breathy root, i.e. it has /je̤/ as its grade 3 counterpart, cf. Table 4 above. In Table 9, similarly, the breathy grade 2 vowel /ɛ̤/ behaves like an /ɛ̤/ in a root with an inherently breathy grade 1 vowel /a̤/, i.e. it has /a̤/ as its grade 3 counterpart, cf. again Table 4 above.

As mentioned above, the distribution of vowel grades in transitive derived verbs is the same in all four root classes. This fact is illustrated in Tables 10–13. Each of these tables shows a paradigm from each root class, centrifugal in Table 10, centripetal in Table 11, dative in Table 12 and dativized antipassive in Table 13. ^[18] The tables also show the inflectionally unmarked form and the non-finite form of the corresponding simple verbs.

3.2 Vowel grades in antipassive verbs

3.3 Range of Fronting in grade 2

In simple verbs, the morphophonological rule of Fronting, which characterizes grade 2, applies only to the low central vowel quality /a/, as exemplified in (4) with the non-breathy root bà̰r ʻtake along’ (Class 1F) and in (5) with the breathy root t̪à̤r ʻspear’ (Class 1F). Vowel grade specification of the verb is indicated in parentheses after the sentences. ^[22]

As seen in the 3SG forms, which are grade 2 forms, Fronting has the effect of changing /a/ to /ɛ/, whether the voice quality is non-breathy (4b) or breathy (5b). In derived verbs, however, Fronting may in addition apply to roots with the rounded lower-mid back vowel quality /ɔ/ (whether non-breathy or breathy) and to roots which have breathy /o̤/ as a raised variant of /ɔ̤/. In that case, Fronting also involves unrounding. I have not examined how common this extension of the range of Fronting is.

Fronting of non-breathy /ɔ̰/ to /ɛ̰/ is seen in derived verbs that do not undergo voice quality shift, i.e., centrifugal verbs with roots of any of the four classes and antipassive verbs with Class 1L roots. The application of Fronting to /ɔ̰/ in centrifugal verbs is illustrated in (6) with the root cɔ̰̀ɔl ʻcall’ (Class 2F).

In (6a) we find the vowel quality /ɔ̰/ as grade 1 in cɔ̰̀ɔl, the inflectionally unmarked form of the simple verb. In (6b) the 3SG form of the simple verb, cɔ̰̀ɔɔl, occurs in grade 2, but has the same vowel quality. In the centrifugal grade 2 forms in (6c-d), Fronting applies optionally, so that the inflectionally unmarked or 3SG form cɔ̰̂ɔɔl varies freely with the fronted variant cɛ̰̂ɛɛl. Centripetal and other derived categories characterized by breathiness are not affected by Fronting since their vowel quality is /o/ rather than /ɔ/, as illustrated in (6e-f).

The application of Fronting to /ɔ̰/ in antipassive verbs with Class 1L roots is illustrated in (7) with the root tɔ̰̀ŋ ʻlight a cow-dung fire’.

As seen in (7b), the 3SG antipassive form varies freely between non-fronted tɔ̰̂ɔŋ and fronted tɛ̰̂ɛŋ.

Fronting may also apply to roots in which /ɔ̰/ is preceded by postconsonantal /j/, as in (8) with the root rjɔ̰̀p ʻpay wages, hire, rent’ (Class 1F).

As seen in (8b), the inflectionally unmarked form of the centrifugal verb has been attested with the fronted form rjɛ̰́ɛp.

Again, Fronting applies optionally in grade 2 to a non-breathy /ɔ̰/ preceded by a postconsonantal /w/, but here with an additional consequence, as illustrated in (9) with the root bwɔ̰̀ɔt̪ ʻfollow’ (Class 2F).

Corresponding to the simple verb with the inflectionally unmarked grade 1 form bwɔ̰̀ɔt̪ in (9a), the centrifugal, inflectionally unmarked grade 2 form bwɔ̰̂ɔɔt̪ in (9b) varies freely with the fronted form bjɛ̰̂ɛɛt̪. In the latter variant, the postconsonantal labiovelar glide /w/ has been replaced with the palatal glide /j/. This is similar to the grade 3 alternant of such verbs, as seen in (9c), where the grade 3 form is bjâ̰aat̪. Thus, the unrounding of /ɔ/ is accompanied by unrounding of the preceding /w/, presumably as a result of assimilation.

In Andersen (1993: 21) it was argued, on the basis of the morphology of simple verbs, that although either of grades 1 and 2 could be considered basic, it is simpler to take grade 1 to be basic. We now see independent and decisive evidence for this analysis in the following fact: The contrast between /a̰/ and /ɔ̰/, which exists in grade 1, is (optionally) neutralized in grade 2 forms of centrifugal verbs. Hence grade 2 cannot be basic.

Fronting of breathy /ɔ̤/ to /ɛ̤/ in derived verbs is illustrated in (10) with the root kɔ̤̀l ʻfan’ (Class 1F).

In (10a-b) the verb ʻfan’ is simple, with the inflectionally unmarked form kɔ̤̀l occurring in grade 1, and the 3SG form kɔ̤̀ɔl occurring in grade 2. In (10c-d) the verb is centrifugal and in (10e-f) centripetal, and the forms given here also occur in grade 2, but with the fronted quality /ɛ̤/. ^[23]

Free inter- and intra-individual variation between the non-fronted quality /ɔ̤/ and the fronted quality /ɛ̤/ is exemplified in (11) with the root ɡɔ̤̀t ʻwrite’ (Class 1F). As seen in (11b), the 3SG antipassive verb varies freely between ɡɔ̤̂ɔt and ɡɛ̤̂ɛt.

In derived verbs, Fronting also applies in grade 2 to breathy /o̤/ preceded by a postconsonantal /w/, as illustrated with the root bwò̤ok ʻslap’ (Class 2F) in (12).

The centrifugal counterpart of the inflectionally unmarked form of the simple verb bwò̤ok in (12a) has the form bjê̤eek, as seen in (12b). As in (9) above, the fronting here has the additional consequence that the postconsonantal /w/ is turned into /j/. This change in the postconsonantal glide is also seen in the grade 3 form bjâ̤aak in (12c) as a result of Lowering. The fact that Fronting applies to /wo̤/ is evidence that /wo̤/ is a raised form of underlying /wɔ̤/, an analysis argued for in Andersen (1993: 16 and 28–29). The fronting in (12b) may thus be said to apply to the underlying form /bwɔ̤̂ɔɔk/ with the output /bjɛ̤̂ɛɛk/, which in turn undergoes raising to the actual form bjê̤eek.

4.1 From /ɔ̰/ to /o̤/, and from /o̰/ to /ṳ/

The shift from non-breathy voice to breathy voice, which is an exponent of derivation, may involve a shift in vowel quality, more specifically a shift in height and, to a more limited extent, a shift in rounding.

The basics of voice quality shift (VQS) are most clearly seen in the antipassive of Class 2H roots, since the set of forms with this derivational status here arguably exhibits all three vowel alternation grades (cf. Section 3.2.5 above), whereas other derivational categories characterized by VQS only involve grades 2 and 3. Table 20 shows, for each of the five non-breathy grade 1 vowels without a preceding postconsonantal glide, the following four forms: the simple verb’s inflectionally unmarked form (which has grade 1) and three representative forms of the antipassive verb, namely the inflectionally unmarked form, which has grade 1, the 3SG form, which has grade 2, and the 1SG form, which has grade 3.

As seen in the table, the unrounded vowels /ḭ/, /ḛ/ and /a̰/ retain their quality in grade 1 when they become breathy. By contrast, the rounded vowels /ɔ̰/ and /o̰/ are raised to /o̤/ and /ṳ/, respectively. Thus, both of them are raised by one step: /ɔ̰/ from lower-mid to higher-mid, and /o̰/ from higher-mid to high. This alternation is completely regular, as illustrated with centripetal verbs in (13) and (14), which show the inflectionally unmarked form of simple verbs and of the corresponding centripetal verbs.

In transitive derived verb categories characterized by breathy voice, there are no grade 1 forms. When a non-breathy /a̰/ becomes breathy in such categories, it either undergoes fronting (and raising) to /ɛ̤/ in grade 2 forms or it is manifested as /a̤/ in grade 3 forms.

Once having become breathy, the vowels in Table 20 conform to the same vowel gradation system as inherently breathy root vowels, cf. Table 4 above.

4.2 From /wɔ̰/ to /o̤/

In grades 1 and 2 of simple verbs, there is complementary distribution between /wɔ̰/ and /ɔ̰/ after an onset consonant (Andersen 1993: 18). Thus, /wɔ̰/ only occurs after labial onsets, while /ɔ̰/ only occurs after non-labial onsets and after a postconsonantal /j/. As exemplified with inflectionally unmarked forms in (15), /wɔ̰/ thus occurs after the labial consonants /p/ (15a), /b/ (15b) and /m/ (15c).

As similarly exempified with inflectionally unmarked forms in (16), /ɔ̰/ occurs after interdentals (16a), alveolars (16b), palatals (16c), and velars (16d).

Given this distribution, Andersen (1993: 18) analyzed post-onset /wɔ̰/ as derived from underlying /ɔ̰/ by a rule of Labialization after labial onsets.

When roots with post-onset /wɔ̰/ undergo voice quality shift, the postconsonantal /w/ disappears, as seen in (17).

The simple verb ‘follow’ has a postconsonantal /w/ in the inflectionally unmarked form bwɔ̰̀ɔt̪ (17a), a /w/ which also occurs in the inflectionally unmarked centrifugal form bwɔ̰̂ɔɔt̪ (17b). But in the breathy forms with this root, there is no postconsonantal /w/, as seen in the inflectionally unmarked antipassive form bò̤ot̪ with grade 2 in (17c), in the inflectionally unmarked centripetal form bò̤oot̪ with grade 2 in (17d), and in the non-finite centripetal form bɔ̤̀ɔɔt̪ with grade 3 in (17e). Thus, /wɔ̰/ (with a postconsonantal /w/) behaves in the same way as /ɔ̰/ (without a postconsonantal /w/), its breathy counterparts being /o̤/ in grade 2 and /ɔ̤/ in grade 3, cf. Section 4.1 above. So VQS does not apply to the surface form with /wɔ̰/, but to the underlying form with /ɔ̰/.

4.3 Raising

In some cases, the voice quality shift involves more vowel quality changes than those dealt with in Section 4.1 above. In particular, some vowels undergo raising conditioned by the preceding consonant. Such raising, which is possibly specific to the Agar dialect, is accounted for in the following subsections. It is argued that in some cases the raising is an integral part of the voice quality shift, whereas in other cases it is due to a separate process.

4.4 From /a̰/ to /ɔ̤/

Another complication in the effect of voice quality shift on vowel quality is found in antipassive forms with Class 2F roots. Antipassive verbs with such roots normally conform to the vowel gradation seen in Table 20 in Section 4.1 above. This is exemplified in (46) with the root d̪ı̰̀im ʻfilter’.

While (46a) shows the inflectionally unmarked form of the simple verb, (46b) shows the inflectionally unmarked form of the antipassive verb, which has the shape CV̤̀VC with a grade 2 vowel. The corresponding grade 3 vowel is seen in (46c).

However, whereas the vowel /a̰/ normally becomes /ɛ̤/ (or /e̤/) in grade 2 when undergoing vowel quality shift, there is a systematic exception to this in antipassive verbs with Class 2F roots. Here the breathy counterpart of /a̰/ either has the normal quality /ɛ̤/ (or the raised variant /e̤/) or it has the quality /ɔ̤/. The distribution of these alternants is determined by the preceding consonant, as can be observed in Table 21, which shows the inflectionally unmarked form of the simple verb and of the antipassive verb.

As seen in the table, /ɛ̤/ occurs after a labial onset, /e̤/ occurs after a postconsonantal glide, and /ɔ̤/ occurs after an alveolar or palatal onset, whereas no instances have been attested in which the vowel occurs immediately after an interdental or velar onset. The variation is exemplified by the sets of clauses in (47)-(50) with the roots mà̰an ʻhate’, t̪jà̰ak ʻmarry’, kwà̰at̪ ʻdrive’ and rà̰ak ‘milk’. The (a)-clauses illustrate the use of the inflectionally unmarked form of the simple verb, and the (b)-clauses illustrate the use of the inflectionally unmarked form of the antipassive verb, while the (c)-clauses show the 1SG form of the antipassive verb.

All the grade 2 variants behave like inherently breathy grade 2 vowels with respect to vowel gradation, as seen in the (c)-clauses of (47)-(50), whose verb has a grade 3 vowel. Thus, /ɛ̤/ and /ɔ̤/ become /a̤/ in grade 3, while /e̤/ becomes /ɛ̤/ after a postconsonantal /w/, but remains as /e̤/ after a postconsonantal /j/.

It is not clear why /ɔ̤/ occurs as a breathy counterpart of /a̰/ here, while the normal counterpart of /a̰/ is /ɛ̤/. Nor is it clear why /ɛ̤/ occurs specifically and only after labials here. As shown in Andersen (1993: 15–16), the quality /ɔ̤/ also appears as the medium counterpart of short breathy /a̤/ in grade 1 of simple transitive verbs. This alternation is exemplified by the sentences in (51).

The inflectionally unmarked form of the simple transitive verb ʻuntie’ in (51a) has a short breathy [a̤], whereas the non-finite form in (51b), which also belongs to the range of vowel grade 1, has a medium breathy [ɔ̤ɔ]. However, this shift from an unrounded to a rounded vowel is independent of the preceding consonant, as seen in Table 22.

Thus, the alternation between [a̤] and [ɔ̤ɔ] or its variant [o̤o] has been attested after onsets that are labial, interdental, alveolar, palatal and labiovelar, and also after postconsonantal /j/ and /w/, while [a̤] has not been attested immediately after a velar onset. As also seen in Table 22, the [ɔ̤ɔ] alternant undergoes Labialization after a labial, and raising after a glide (Andersen 1993: 16–17).

As pointed out in Andersen (1993: 15–16), positing a rule that rounds a non-short breathy /a̤/ to /ɔ̤/ also accounts for the absence of simple transitive verbs with a medium breathy /a̤/ in the inflectionally unmarked form and the corresponding presence of simple transitive verbs with a medium breathy /ɔ̤/ in this form. Again, the occurrence of this /ɔ̤/ and its raised variant /o̤/ is not constrained by the preceding consonant, since it occurs after consonants with all points of articulation, as seen in Table 23. As also seen in this table, /ɔ̤/ is raised to /o̤/ after a postconsonantal glide.

4.5 Summary of voice quality shift

The basics of voice quality shift are summarized in Figure 1. The arrows show the shift from non-breathy grade 1 vowels to the corresponding breathy grade 1 vowels and subsequently grades 2 and 3 of these breathy vowels. Excluded from the figure are (i) special vowel quality changes connected with preceding postconsonantal glides and (ii) variants that are the effect of raising caused by the preceding consonant.

Figure 1:

Voice quality shift and vowel height gradation.