Phonology of Adur Niesu in Liangshan, Sichuan

: This study describes the segmental and suprasegmental phonology of Adur Niesu, a Loloish (or Ngwi) language spoken mainly in Liangshan, Sichuan, southwest China. Phonemical-ly, there are 41 consonants, 10 monophthongs and 1 diphthong in Adur Niesu. All Adur syllables are open. Its segmental changes mainly happen to the vowels, featuring high vowel fricativization, vowel lowering, vowel centralization, vowel assimilation and vowel fusion. It is common for Adur Niesu syllables to be reduced in continuous speech, with ﬂ oating tones left. There are three main types of syllable reduction: complete reduction including the segment and tone, partial reduction with a ﬂ oating tone left, and partial reduction with the initial consonant left. Adur Niesu employs tones as an important means for lexical contrast, namely, high-level tone 55, mid-level tone 33, and low-falling tone 21. There is also a sandhi tone 44. There are two types of tonal alternation: tone sandhi and tone change. Tone sandhi occurs at both word and phrasal levels, and is conditioned by the phonetic environment, while tone change occurs due to the morphosyntactic environment. Finally, some seeming tonal alternation is the result of a ﬂ oating tone after syllable reduction.


Introduction
Adur Niesu is a member of the Nisoic (aka. Loloish or Ngwi) subgroup of the Niso-Burmese (i.e., Burmese-Lolo) language group of the Tibeto-Burman languages (Bradley 1997;Lama 2012). It is spoken by about 440,000 people, who are officially recognized as Yi (彝族), residing in mountainous regions in Liangshan (literally 'Cool Mountains'), Sichuan, in southwest China. The Adur Niesu people often call themselves simply Adur, which is said to be the surname of a famous ruling clan living in Butuo (or ndʑi 55 la 33 pu 44 t h ɯ 33 ) in eastern Liangshan. Adur is often associated with the title ndzɨ 33 mo 21 (lord caste:master) 'highest lord caste' and its variant ndzɨ 21 mo 21 (lord caste:big) 'big (accomplished) highest lord caste', namely, a 33 tu̠ 33 ndzɨ 33 mo 21 and ndzɨ 21 mo 21 a 33 tu̠ 33 . It is noted that the tone on the morpheme meaning 'lord caste' is different when it is before and after Adur, namely, ndzɨ 33 and ndzɨ 21 . This reflects a tone change that will be discussed in Section 4.4.3. When ndzɨ 33 mo 21 is placed after Adur, without any tone change, it functions as a title, similar to the structure in su̠ 33 ga 55 ma 55 mo 21 (surname teacher) 'Mr. Suga'. When ndzɨ 21 mo 21 is placed before Adur, with a tone change, it is a nominal modifier meaning 'big (accomplished) lord caste', similar to dza 44 ndo 33 vi 33 su̠ 33 ga 55 (food:swallow:type surname) 'Suga, big eater'. The Adur Niesu people mainly live in Butuo (布拖县), Puge (普格县) and Ningnan (宁南县), with some Adur population located along the border with Jinyang (金阳县) and Zhaojue (昭觉县); see Figure 1.
Moreover, Adur people also call themselves Niesu [njɛ 33 su 33 ]. This autonym is shared by another group of Yi people adjacent to the Adur region, called Suondi Niesu or simply Suondi or Niesu; see Figure 1. Niesu [njɛ 33 su 33 ] has two meaning-bearing morphemes, namely, [njɛ 33 ] 'black ' and [su 33 ] 'people', which literally means 'black people'. The population of Suondi Niesu is around 550,000, estimated according to Chen et al. (1985); Gerner (2013)  There are three recent studies about Niesu phonology, mostly focusing on Suondi Niesu in Mahai (2015Mahai ( , 2019 and in Mise (2020). Since Suondi Niesu is very close to Adur Niesu, these works are important references to understand Adur Niesu. But there is still room to improve the accuracy and adequacy of the analysis. Although some phonetic information, i.e., Adur consonants, vowels and tones, are presented in Sun's (2020) construction of an Adur phonetics corpus, there is little research on the phonology. Therefore, this study will contribute to the literature by describing the phonological system of Adur Niesu. The Adur Niesu data presented in this paper are first-hand fieldwork data collected through spontaneous narration and elicitation, mainly based on the Tuojue dialect spoken in central Butuo, Liangshan. The fieldwork in Tuojue (or 拖觉镇), Butuo, started in 2018 and there have been five trips so far; each trip lasted for about two months. The two main consultants are Adur Niesu native speakers who are in their 30s. They started to learn Chinese after they were 10 years old in school and became fluent in Chinese around the age of 18. The data presented in the paper were also cross checked with elder speakers aged from 50 to 70 in Butuo, Liangshan. Although a series of studies have been devoted to the labiovelar sounds in Adur Niesu (i.e., kp, kph, gb, gb, ŋm) (Pan 2001;Matisoff 2006;Hajek 2006;Bradley 2008), such sounds are not found in the Tuojue dialect. 1

About Adur Niesu
Based on the subgrouping in Hammarström et al. (2022), Adur Niesu is a verb-final syllable-tone Burmo-Qiangic language; see Figures 2 and 3. Its morphology is largely isolating. A large number of phonemic consonants in Adur Niesu are generated by voicing, aspiration and prenasalization. The grammatical function of Adur Niesu is mainly conveyed by using clitics and postpositions. Property-denoting modifiers follow the head noun. However, noun and genitive modifiers precede the head noun. Tense is not a grammatical category in Adur Niesu. The relation of the event time to some temporal reference point is expressed by lexical means, such as a 21 ŋu 33 'now', a 21 ȵi 55 'the past' and i 21 sɛ 21 ʂɿ 44 a 33 ɬo 44 'the ancient past'. Its aspectual classes are expressed strictly analytically, by verbal enclitics, TAM auxiliaries, and periphrastic constructions. Adur Niesu forms its yes/no questions by reduplicating the last syllable of the verb or auxiliary. It is topic-prominent, frequently employing topic-comment constructions.
A close dialect of Adur Niesu is Nuosu. Nuosu, also meaning 'black people', is a relatively well-studied variety of Nuosu proper (Chen et al. 1985;Bradley 1990;Chen and Wu 1998;Lama 1998;Hu 2001Hu , 2010Gerner 2013). Both Niesu and Nuosu are classified under Nuosu proper (Lama 2012); see Figure 3. People using the autonym of Nuosu include Shynra, Yynuo, and Qumusu speakers, whose population is estimated to be about 1.9 million (Bradley 2001).  The mutual intelligibility between Adur Niesu and Nuosu is relatively low (Bradley 2001), which is mainly due to phonological differences (see Table 1, and also Pan 2001;Matisoff 2006;Hajek 2006;Lama 2012 The identical words are highlighted among Adur Niesu, Suondi Niesu and Shynra Nuosu. While Adur shares many words with Suondi Niesu, it is phonologically different from Nuosu. If their geographic distribution is considered, Suondi Niesu is sandwiched between Adur Niesu and Nuosu. According to Lama (2022), there are two shared phonological innovations in Adur Niesu and Suondi Niesu, making them different from Nuosu. The first one is the lenition of the voiceless nasals, namely, making the voiceless nasals m̥ and n̥ voiced; see Table 2. The second innovation is that the *o sound in Proto-Nuosu proper is fronted and raised to i in Adur and Suondi Niesu; see Table 2. There are additional innovations to subgroup Adur Niesu and Suondi Niesu under one node, and support Lama's (2022) claim that they should be the first group to branch off from Proto-Nuosu proper. For example, the Proto-Loloish (PL) stops in Table 3 change to affricates in Adur and Suondi Niesu. It is also interesting to observe an intermediate stage towards affrication in the Jiaojihe (literally 'intercourse river' or 交际河) variety of Adur Niesu, which is to the south of Butuo and adjacent to the northeastern border of Yunnan. In Jiaojihe variety, the velar plosive is kept and the fricative is epenthesized. This could be considered as a shift of place of articulation from velar plosive to retroflex affricate, and is probably a feature of Proto-Adur Niesu. The reconstruction *kwe 2 (PL), *pre 1 (PL), and *ʔ-kutᴸ (PL) are taken from Bradley (1979); *kʷəy¹ (PLB) and *m-ka-n (PTB) from Matisoff (2003).
Another innovation is the insertion of a medial /w/ to form diphthongs after velars (see Matisoff 2006;Bradley 2008). See examples in Table 4. The diphthongization is still stable in Adur Niesu. According to Lama (2022), the diphthongization, however, is being lost among young Suondi Niesu speakers, while this feature has still been kept among the elder Suondi speakers. Moreover, velars in Nuosu are more palatalized in Suondi Niesu and Adur Niesu, if followed by the front vowel /i/ (see Table 5). There are also phonological features which make Adur Niesu distinctive from Suondi Niesu. Table 3 shows that Adur Niesu retroflexizes the alveolar affricates in Suondi Niesu. The retroflexization, as a typical feature of Adur Niesu, is the reflex of PL or PTB *r and PL *ʃ or *s; see Table 6. All reconstructions are taken from PL in Bradley (1979), except *m/s-kri(y)-s (PTB) from Matisoff (2003).
Vowel-wise, the front vowel /i/ in Suondi Niesu, as well as Nuosu, corresponds to back vowel /ɯ/ in Adur Niesu if they are preceded by alveolo-palatal sounds (see Table  7).

Segmental Phonology
This section starts with Adur Niesu consonants and then moves on to vowels. After introducing the syllable and the phonotactics, segmental changes in both vowels and consonants will be covered. Table 8 demonstrates the 41 phonemic consonants of Adur Niesu: nine plain plosives, three prenasalized plosives, eleven fricatives, four nasals, two laterals, nine affricates and three prenasalized affricates. Suondi Niesu has the same consonant inventory as Adur Niesu (Lama 2012;Mise 2020). Compared with Nuosu, Adur Niesu lacks voiceless nasals /m̥ / and /n̥ / (see Section 2). Depending on whether a consonant can precede either the unrounded palatal [j] or the rounded labiovelar [w], Adur Niesu consonants can be divided into two groups: the J-group, marked in the solid box, and the W-group, marked in the dotted box. The other consonants cannot be followed by the glides. The plain plosives are differentiated from the prenasalized plosives (see Section 3.1.5). They are produced through three places of articulation: bilabial, dental, and velar, as shown in Table 9, respectively. The three-way contrast among the plain plosives is achieved with voiced vs. voiceless unaspirated vs. voiceless aspirated. While the velar group cannot go with the J-glide, the bilabial and dental groups cannot go with the W-glide. It should be noted that the diphthongs [jɛ] and [wɛ] are two allophones of /ɛ/ and [wi] is an allophone of /i/ (see Section 3.2.1). The eleven fricatives are articulated at six places: bilabial, dental, retroflex, alveolopalatal, velar and glottal (see Table 10).

. Nasals and Laterals
The nasals have four places of articulation: bilabial, dental, alveolo-palatal and velar, and the laterals have just one: dental (see Table 11). Niesu, both Adur and Suondi, has three sets of affricates, produced at dental, retroflex and alveolo-palatal, respectively. Each set shows a three-way contrast in terms of voicing and aspiration, as exemplified below (see Table 12). Voiced plosives and affricates are prenasalized in Adur Niesu (see Table 13). The prenasalized consonants are treated here as unitary segments, not consonant clusters, on the ground that (1) they are contrastive with other consonants, such as ndo 21 'to fall down' vs. do 21 'speech, word', ŋga 33 'be clever' vs. ga 33 'road', and nɖʐa 33 'to sprinkle water for cooking the corn rice' vs. ɖʐa 33 'sparrow'; (2) the nasal is always homorganic with the following plosives or affricates; and (3) the nasal-obstruent onsets only appear in the syllable-initial position. Lama (1998) also considers prenasalized obstruents in Nuosu, a close dialect of Adur Niesu, unitary segments, not consonant clusters, after acoustic analysis. Adur Niesu distinguishes between two glides: the unrounded palatal j and the rounded labiovelar w. The former is non-phonemic and the latter is phonemic. The glides are treated as part of the rhyme of a syllable, but not an element in a complex consonant. The reason is based on economy. By doing this, the sum of the diphthongs formed by the two glides is only four, including three allophonic diphthongs, [wɛ], [wi] and [jɛ] (see Section 3.2.1), and one phonemic diphthong, /wa/ (see Section 3.2.4), exemplified below. Bradley (2008) treated the glide /w/ as an element in complex consonants, or labialized velars. However, if similar treatment is made to the glide j, there would be as many as 17 complex consonants, including 13 allophonic complex consonants, such as
It should be noted that the Adur vowel /ɯ/ is more advanced and lower than the cardinal IPA [ɯ]. Due to this deviation, it is not impossible to transcribe this vowel as /ə/, such as in the Nuosu vowel inventory in Lama (2002). In the present study, /ɯ/ is used, mainly because the Adur Niesu /ɯ/ is categorically closer to the cardinal IPA [ɯ] in terms of vowel height and backness. This symbol /ɯ/ is also adopted in describing Nuosu vowels (Lama 1998;Edmondson et al. 2017).
Another way of organizing Niesu vowels is to categorize them into tense and lax vowels (Chen et al. 1985;Lama 2002) (see Table 14). This is useful for the description of vowel assimilation (see Section 3.4.2). It should be noted that the tense/lax contrast in the tradition of Southeast Asian languages have been applied in reversed fashion to the terms that are used in talking about Germanic languages (Maddieson and Ladefoged 1985). The principal component of the tense/lax distinction in Adur Niesu, as well as other Yi languages, is a difference in the laryngeal setting, namely, the tense vowels are more laryngealized than the lax ones (Lama 2002;Esling and Edmondson 2002). Therefore, the lax vowels are closer in the vowel space and, thus, higher, while the tense vowels are more open and, thus, lower (Edmondson et al. 2017). Therefore, Adur Niesu monophthongs can be paired as below. This pairing also displays frequent assimilation results discussed in Section 3.4.

Central Vowels
Adur central vowels contrast one another in terms of height. The contrast between ɨ and ɨ̠ , regarding the retractedness or tenseness, also exists in Nuosu (Edmondson et al. 2017 Vowels ɨ and ɨ̠ only occur with 17 consonants: the three plain bilabial plosives, the six dental fricatives and affricates, the six retroflex fricatives and affricates, and the two dental laterals. Both of them are subject to high vowel fricativization, each having two allophones in the form of fricative vowels, namely, [z̩ ] and [z̩ ̠ ], when they follow the plosives and the dentals, and [ʐ̍ ] and [ʐ̍ ̠ ] when they follow the retroflex sounds. Therefore, the phonetic realizations of the examples in (11) are (12a) to (12d). See more examples in (12e) to (12m). According to Edmondson et al. (2017, p. 89), Nuosu expresses 'dragon' with the fricative vowel [v] as an allophone of /u/, thus transcribed phonetically with labialization: l˞ ʷː 33 'dragon' (cf. lu 33 as the phonemic form). However, in Adur Niesu, lip rounding is not observed in the pronunciation of 'dragon' (see 12l) or in the other examples transcribed with labialization in Edmondson et al. (2017). Therefore, the laterals are incompatible with /u/ and /u̠ / in Adur Niesu. Similar to Nuosu, the laterals in Adur Niesu will end up being rhoticized after the high vowel fricativization. Similar rhoticization is reported in Ersu, a Na-Qiangic language spoken in Liangshan (Chirkova and Handel 2013

Back Vowels
Similar to /ɨ/ and /ɨ̠ /, the vowel /u/ contrasts with /u̠ / in terms of retractedness. Although the Adur vowel /ɯ/ is more advanced and lower than the cardinal IPA [ɯ], it is discussed with other back vowels. 14 a p h u 33 'price, value' p h u̠ 33 'to dig' b ʂu 33 'to do' -ʂɯ 33 'to find' c ŋgu 33 'to boast' ŋgu̠ 33 'to rub with hands' ŋgɯ 33 'buckwheat' The phonemic contrast between /u/ and /u̠ / is not symmetric. Consonants that can occur with /u/ may not have a contrast with /u̠ /. For instance, zu 33 'to irritate' has no contrastive pair as *zu̠ 33 , and k h u 33 'to steal' lacks a contrast as *k h u̠ 33 . It is, therefore, observed that /u/ and /u̠ / start to merge as one phoneme. According to the main consultants, the following pairs are interchangeable, showing free variations. Another observation is that the retracted /u̠ / is forming a complementary distribution with /u/ by occurring with the high-level tone 55 only. While the lax /u/ bears tone 33, the tense /u̠ / bears tone 55 in (16). Mise (2020) also indicates that tone 55 causes vowel tenseness in Suondi Niesu. Therefore, it is possible for the two phonemes to merge or become allophonic in the future. 16 a du 33 'wing' *du̠ 33 du̠ 55 'be stealthy' b ŋu 33 'be' *ŋu̠ 33 (kɔ 33 lɔ 33 )ŋu̠ 55 'be angry' c tu 33 'to lift' *tu̠ 33 tu̠ 55 (m̩ 33 ) 'be promising' Both /u/ and /u̠ / are noteworthy in that they lead to syllabic consonants if they are preceded by /m/. It was clearly observed from the consultants that the two syllables below were not produced with any rounding of the lips. A final feature of /u/ and /u̠ / is that they may be substituted with a syllabic bilabial trill [ʙ̩ ] after labial and dental plosives. The trill substitution is subject to personal habit, thus forming free variation. But the trill substitution is more preferred after voiced labial and dental plosives, and less preferred after voiceless ones. While no diphthong is reported in the Nuosu vowel inventory (Lama 1998(Lama , 2002Gerner 2013;Edmondson et al. 2017), different numbers of diphthongs in Suondi Niesu are reported: /ie ui ue/ in Lama (2012), /uɑ ue ui/ in Mahai (2015) and /ua ui/ in Mise (2020). Due to the close relation between Suondi and Adur Niesu, it is suspected that not all reported diphthongs in Suondi Niesu are phonemic. In

The Syllable and Phonotactics
Adur Niesu syllable structure is relatively simple. All are open syllables. Adur Niesu segments are organized into syllables as below (see Figure 4). The onset can be any of the 41 consonants. The on-glides are either j or w. The vowel slot can be filled by any of the 10 monophthongs or the syllabic consonants if there is no glide in the syllable. The J-glide only occurs with /ɛ/, and the W-glide occurs with all front vowels, namely, /i/, /ɛ/ and /a/. But syllables involving a glide must be preceded by an onset, such as (22a) to (22f). In this case, all slots are filled. The onset and on-glide slots can be optional; see (22g)  Without considering the three basic tones of Adur Niesu, there are 308 attested syllables. Allophonic realizations are indicated in Table 15.

Segmental Changes in Vowels
In the previous sections, some vowel changes were discussed: allophones of the front vowels in Section 3.2.1, occasional vowel reduction in Section 3.2.2, and high vowel fricativization in Sections 3.2.2 and 3.2.3. In the present section, another four vowel changes are presented: vowel lowering, vowel centralization, vowel assimilation and vowel fusion.

Vowel Lowering and Centralization
The high vowel /u/ may be lowered to /o/, forming a free variation. The reason why the change is considered a lowering, rather than a raising, is that the high vowel /u/ is more common in the speech of both the elder and young population.

Vowel Assimilation
Vowel assimilation is another case of vowel lowering in Adur Niesu. Nearly all assimilations in Adur Niesu are regressive, and most occur between tense and lax vowels (see Section 3.2), namely, the preceding lax vowel will be lowered to a tense vowel, or become more laryngealized; see Table 14. Recall in Section 3.2 that the tense vowels are treated as those which are more laryngealized than the lax ones, and thus have a lower position than the lax ones (Maddieson and Ladefoged 1985;Lama 2002;Edmondson et al. 2017). Therefore, the rhyme of the first syllable is assimilated in terms of the tenseness of the following rhyme. Compare the examples in (25a) to (25d). /ɛ/, /a/ and /ɨ̠ /, belonging to the tense group, lower the vowel of the first syllable from the lax one to its tense counterpart, namely, from Some of the assimilations are more phonetic in nature, since they can be restored to the original vowel in slow and careful speech; but some are more morpholexical in nature, since they cannot be restored to the original vowel, even using slow and careful speech. If restoration is forced in the latter case, new meanings will be produced. All examples in (27) are phonetic assimilations and those in (28)  The tenseness/laxness-induced assimilation can also be relative. As long as the following vowel is tenser, or lower, than the preceding vowel, regressive assimilation can be triggered. For example, although /o/ is laxer than /ɔ/, it is tenser and lower than /ɯ/; therefore, assimilation occurs in (29). Since /u/ is not tenser than /i/, assimilation is not triggered in ȵi 21 bu 21 'two households' in (25c) (cf. ȵɛ 21 ma 33 'two pieces').

Vowel Fusion
Vowel fusion in Adur Niesu results in vowel substitution of the rhyme of the preceding syllable, such as ʑa 33 (ʑi 33 'to go' + a 33 'attitudinal marker') 'let's go'. Although it is also possible for vowel fusion to occur intraclausally, it is more common at the clause end. In (30) and (31), the rhyme of the first syllable is replaced by the following vowel at the clause's final position, and in (32), the vowel fusion occurs in the clause.

Segmental Changes in Consonants
Segmental changes in Adur Niesu consonants are not widely observed. Lenition and clanlects are presented.

Lenition of the Velar Consonants
Briefly, the velar stops can be lenited in spontaneous speech as velar fricatives; see (33). Variations in aspiration change between different clans are found, or 'clanlects'. One of the main consultants is a descendant of the dʑɛ 21 nɛ 33 clan, and another one is of the su̠ 33 ga 55 clan. Both of them live in the same village since they were born. The following two words are not aspirated in the speech of the dʑɛ 21 nɛ 33 descendant, while they are aspirated in the speech of the su̠ 33 ga 55 descendant. But the aspirated affricate in the three words has wider usage among Adur Niesu speakers. Other than the two words, both consultants share similar phonological system of Adur Niesu. d ʑɛ 21 nɛ 33 clan su̠ 33 ga 55 clan 34 a 'he, she, it' tsɨ 33 ts h ɨ 33 b 'this' tsɨ 33 ts h ɨ 33

Syllable Reduction
It is common for Adur Niesu syllables to be reduced in continuous speech. There are three types of syllable reduction being observed in the field: complete reduction including the segment and tone, partial reduction with a floating tone left, and partial reduction with the initial consonant left.
The syllable is so reduced that a particle is left to signal the existence of a clause; see (35b) where ts h ɨ 21 mu 33 'doing so' is reduced. It is often the segments of the whole syllable being deleted. After the reduction, the tone becomes a floating tone and reassociates itself onto the preceding syllable. For example, in (36a) to (36c), the second syllable is reduced, namely, ʂɨ in a 33 ʂɨ 55 'what', sɨ in a 21 sɨ 21 t h ɯ 33 'when' and hi in a 21 hi 33 'cannot'. But the tone is left. The tonal trace can be observed on the remaining preceding syllable. Namely, the original tone of the preceding syllable is overridden by the floating tone, where a 33 changes to a 55 in (36a) and a 21 changes to a 33 in (36c). Since the first syllable a 21 bears the same 21 tone with the deleted syllable in (36b), the overriding is not evident. In (36a) and (36b), other than the syllable reduction, the fricative glottal /h/ can often be epenthesized, namely, ha 55 and ha 21 . In a polar interrogative, on the surface, there seems to be a tone change: 55 > 21 / 55 _. However, the tone lowering from 55 to 21 is not a tone change (cf. tone sandhi in Section 4.2 and 4.3), but in fact the result of the floating tone associated with the interrogative particle a 21 after syllable reduction, which is exemplified below. The floating tone of the interrogative particle overrides the tone of the preceding syllable. Meanwhile, the preceding high front vowel [i] is assimilated by the interrogative particle a 21 and lowered to [ɛ] (see Section 3.4). If the lowered vowel [ɛ] occurs with the J-group consonants, it will subsequently change to the phonetic diphthong allophone [jɛ], namely, pɛ 21  It is particularly useful to contrast the above syllable reduction with reduplication for intensification in Adur Niesu. Without the effect of the interrogative particle, when two high-level tones are adjacent to each other, there is no change of the tone and of the vowel. Moreover, the syllable reduction also occurs to other vowels bearing the high-level tone 55; see (39a) to (39c), accompanied by vowel assimilation. However, the syllable reduction does not occur to syllables bearing other non-high-level tones; see (39d) and (39e). Likewise, the vowel assimilation will not occur. Sometimes, the syllable may not be completely reduced, leaving not only the tone, but also the onset. The leftover will go with the preceding syllable; see (40). Mahai (2019) reports another kind of partial reduction, namely, the initial consonant is deleted, with only the rhyme left, such as ʑa 21 o 55 for ʑa 21 ʑo 55 'potato' and ŋo 21 i 55 for ŋo 21 ȵi 55 'the two of us (exclusive)'. However, we did not have a similar observation about this reduction in Adur Niesu in the field. '(Someone) said that at this exact moment, (you) took an official seal and went to give (it) to Uolamuhi who is from the Adur region.' Syllable reduction can also create the environment for vowel assimilation. For example, ts h ɨ 21 mu 33 ɔ 44 nɔ 33 (this do if) 'if it is like this' changes to ts h ɔ 33 ɔ 44 nɔ 33 , with the syllable mu 33 being deleted, namely, ts h ɨ 33 ɔ 44 nɔ 33 , and tone 33 being reassociated to the preceding syllable and the rhyme then being assimilated by the following tenser vowel ɔ.

The Suprasegmentals
Adur Niesu employs suprasegmentals as an important means for lexical contrast, like many other syllable-tone languages of East and Southeast Asia. In Adur Niesu, two types of tonal alternation should be distinguished: tone sandhi and tone change. Similar distinction is made in Prinmi (Ding 2014) and in Yongning Na (or Narua) (Michaud 2017).
Tone change is governed by rules that are confined to specific morphosyntactic environments. It is the dominant form of tonal alternation in Adur Niesu. The tone change appears in the following morphosyntactic contexts: (1) compound words, (2) prefixed words, (3) patient marking, and (4) yes-no interrogation generated by reduplication.
Finally, floating tones in Adur Niesu can generate a surface kind of tonal alternation, although, in fact, it is the result of syllable reduction. After the syllable reduction, the tone becomes a floating tone and reassociates itself onto the preceding syllable, such as the so-called tonal change regarding the possessive pronouns, where the tone of the reduced genitive marker *ni 21 of Proto-Nuosu proper was retained by the plain personal pronouns in Adur Niesu.

The Three Basic Tones
Identical to Suondi Niesu, Adur Niesu has three basic tones: high-level tone 55, mid-level tone 33, and low-falling tone 21. The minimal contrast between these three tonal categories is exemplified below (see Figure 5).  There is a 44 (high-mid level) tone in Adur Niesu. See Bradley (1990) for the discussion of tone 44 in Nuosu. However, it is seen largely in cases of tone sandhi, which often results from either tone 33 or tone 21 in syllable combination. There is no co-occurrence of tone 44 with tone 55 at the lexical level. In Figure 6, tone 44 is slightly higher than tone 33 in the word pi 33 mo 44 'priest', but tone 55 is much higher than tone 33 in the word nɛ 33 ndʐa 55 'pretty woman'. Tone 44 often appears in particles at the clause boundary, such as the sequential clitic ɕi 44 and change of state clitic o 44 in (43), and clause linker lɯ 44 in (44). If the clause boundary is occupied by content words, tone 44 is not used, such as lɨ̠ 33 'to trap' in (44). If not used at the clause boundary, tone 44 only appears in a few morphemes in Adur Niesu as citation forms, namely, mo 44 as a hesitator, sa 44 the comitative, di 44 the quotative, and ȵo 44 the experiential clitic. '(The horse, the bull and all the big beasts) stamped on (the frog) into the mud, (who was) being stuck firmly in the road2, and (the frog) could not come out, staying there,….'

Tone Sandhi: 33 > 44 / _ 33
The most productive tone sandhi in Adur Niesu is 33 > 44 / _ 33, regardless of the morphosyntactic environment. Other phonological processes may also occur, such as vowel assimilation in (45f)  This sandhi rule can also mark the compounding of the verbs. The rise to tone 44 suggests that it is a compound word and the interpretation is from left to right; see (46). But if the tone is not raised, namely, xɯ 33 dzɯ 33 and ŋɯ 33 dzɯ 33 , the interpretation of xɯ 33 and ŋɯ 33 changes to 'meat' and 'fish', respectively. The expressions are thus understood as phrases, not words, meaning 'to eat the meat' and 'to eat the fish'.
This tone sandhi seldom occurs in phrases in Adur Niesu. In (47), where all expressions can be understood as phrases, this sandhi rule does not apply. For example, (47d) does not refer to a particular kind of snake, but a generic term to cover all snakes living or happening to be found in the water. However, this restriction seems less rigid in Nuosu. Gerner (2013) reported that the demonstrative would rise to tone 44 in Nuosu if there was a following classifier of tone 33, such as ts h ɨ 44 ma 33 (this CLF) 'this one' and ts h ɨ 44 bo 33 (this CLF.PL) 'these ones'. In contrast, the tone of the demonstrative is not raised in Adur Niesu, namely, ts h ɨ 33 ma 33 'this one'. According to the Adur consultants, if the demonstrative is raised in tone, it means emphasis. It is more natural to keep the original tone 33 in this combination. 47 a ʐɨ 33 'water, river' + dʑi 33 'clean' → ʐɨ 33 dʑi 33 'clean water' b lɯ 33 'cow' + tʂ h ɨ 33 'manure' → lɯ 33 tʂ h ɨ 33 'cow's manure' c ɣo 33 'bear' + ʈʂɨ 33 'bile' → ɣo 33 ʈʂɨ 33 'bile of the bear' d ʐɨ 33 'water, river' + ʂɨ 33 'snake' → ʐɨ 33 ʂɨ 33 'snake(s) in the water (not a kind of snake)'

Tone Change in Compounds
Compounding is a productive means of word formation in Adur Niesu. Tone change can serve as a phonological criterion to distinguish compound words from phrases. The two rules of tone change are discussed together since both of them occur in similar semantic environment, namely, about the masculine gender of animate beings. The words are compounded with an animal formative and the masculine morpheme pa 55 and pu 33 . Morpheme pa 55 is a reflex of PTB *p/ba 'male, father, 3 rd pronoun' and pu 33 is of PTB *pu 'male, masculine suffix' (see Matisoff 2003). Adur Niesu uses the former to refer to 'parents', namely, p h a 55 mo 55 , with additional aspiration. Both pa 55 and pu 33 will cause the preceding 33 tone to be lowered. The dog word tʂ h ɨ 33 can go with either masculine morpheme, and its tone is lowered in both compounding; see (53a) and (53g). Bearing the male morpheme pa 55 , the word 'horse' mu 21 pa 55 has extended its meaning to cover both male and female horses. As a consequence, another gender morpheme is needed to specify whether it is a male or female horse in modern Adur Niesu, namely, mu 21 pu 33 'male horse' and mu 21 mo 21 'female horse'. In some cases, the masculine marker pu 33 is voiced, such as in lɛ 21 bu 33 'ox', but the tone change rule still holds. However, if the preceding syllable bears the 55 tone, it will not be lowered due to the masculine syllable, for example, tʂ h ɨ 55 bu 33 'male goat' and vi 55 pa 55 'female pig'.

Tone 33 > 21/_ mo 21
This tone change occurs if the preceding syllable bearing tone 33 is followed by the feminine morpheme mo 21 , a reflex of Proto-Loloish *ʔəC-ma³ 'mother' (Bradley 1979). Like many Tibeto-Burman languages, Adur Niesu mo 21 can also function as an augmentative morpheme (see Matisoff 1992). This rule of tone change is effective if mo 21 is used for two functions, i.e., a feminine marker and an augmentative marker, regardless of the animacy of the word. If the preceding syllable does not bear tone 33, this tone change does not apply, such as vi 55 mo 21 (pig:female) 'female pig' and tɕi 55 mo 21 (eagle:female) 'female eagle'. Similar to the masculine marker pa 55 in mu 21 pa 55 which covers both male and female horse as a general term, mo 21 can also be lexicalized with its feminine meaning being implicit, such as dʑɯ²¹mo²¹ 'bee, queen bee'. But this rule of tone change still holds because of the feminine marker.
However, this tone change does not apply to other meanings derived from mo²¹. In Adur Niesu, besides 'female' and 'big', mo²¹ can also function as a nominal meaning 'woman' and 'master', such as nɛ 33 mo 21 (black Yi:woman) 'the women of the Black Yi (the historical noble class)', ma 55 mo 21 (teach:master) 'teacher', and a postposed modifier meaning 'old', such as ts h o 33 mo 44 (people:old) 'old people' and ɣo 33 mo 44 (bear:old) '(old) bear'. This tone change does not apply to the above three meanings. Note the contrast between pi 33 mo 44 'priest' and pi 21 mo 21 'big (highly experienced) priest'. The former is a general term and also the title to refer to a Yi priest, and the latter is only used for priests with experiences and achievements. For example, while dʑɯ 33 k h ɯ 33 pi 33 mo 44 means simply 'Priest Jike', pi 21 mo 21 dʑɯ 33 k h ɯ 33 is a nominal-nominal phrase, meaning 'Jike, the highly experienced and accomplished priest'. Additionally, this rule of tone change serves as a criterion to distinguish two confusing meanings in Adur Niesu, namely, 'old' and 'big'. In many languages of the world, 'old' and 'big' can be colexified (Rzymski et al. 2019). If this tone change occurs in compound words, the meaning is not 'old', but 'big', for example, sɨ̠ 21 mo 21 'big tree'. To express 'old tree', a phrase is needed, namely, sɨ̠ 33 a 33 mo 21 (tree old) 'old tree '. 4.4.4. Tone 33 > 21/_ ȵi 55 This rule of tone change occurs in the semantic environment of dual marking, with the plural pronouns compounded with the dual morpheme ȵi 55 . It should be noted that the dual marker ȵi 55 is derived from, but different from, the cardinal word ȵi 21 'two'. This can be proved by the evidence from a 33 sɨ 55 ȵi 55 (1PL.inclusive dual) 'the two of us (inclusive)' where, without tone 33 on the preceding syllable, the dual marker still bears tone 55, not tone 21. Otherwise, ȵi 21 will be considered to colexify 'dual' and 'two', which is an unlikely proposal for Adur Niesu.

Tone 33 > 44/ ha 21 _
This tone change occurs in interrogatives of quantity, such as 'how many' and 'how long'. The interrogative words are compounds, formed by the interrogative morpheme ha 21 and the adjectival roots; see Table 16. Both ha 21 and the adjectival roots are bound morphemes, and cannot be used as full words. This tone change is also found in Nuosu; see Table 16. Adur Niesu ha 21 should follow the derivational chain from the category of selection a 21 sɨ 21 'which' to the category of manner ha 21 mu 33 (how:do) 'how'.
First, typologically, the derivational direction from the interrogative category of selection to that of manner is attested, not the other way around (see Hölzl 2018, p. 83). Second, Adur Niesu ha 21 'how' and a 21 sɨ 21 'which' are closely related; the former should be a form after syllable reduction of the latter. After the syllable reduction of sɨ from a 21 sɨ 21 , a fricative glottal /h/ can often be epenthesized, such as ha 21 ʐɨ 44 / a 21 ʐɨ 44 'how big?' and ha 21 ȵo 44 / a 21 ȵo 44 'how many?'. The epenthesized form now becomes the dominant form of this morpheme. A similar epenthesis is shown in (36).
Adur Niesu ha 21 can be interchangeably pronounced as a 21 sɨ 21 as in a 21 sɨ 21 mu 33 / ha 21 mu 33 (how:do) 'how' and as a 21 sɨ 21 t h ɯ 33 / ha 21 t h ɯ 33 (which:time) 'when'. Therefore, a 21 sɨ 21 means both 'which' and 'how' in Adur Niesu. Treating a 21 sɨ 21 as the how form in Adur Niesu is attested by PL *ʔəs (Bradley 1979, p. 334). The Nuosu k h ɯ 21 should be a reflex of the Proto-TB *ka (Matisoff 2003). Unlike Adur Niesu, Nuosu k h ɯ 21 has lost its etymological connection with its modern which word ɕi 44 (Shynra) and ɕa 42 (Yynuo). The possible reason is that, at a certain historical moment, there used to be two which words in Nuosu: the canonical which lexeme, cognate of the Proto-TB *ka, and an innovation derived from other interrogatives (e.g., where and what). Gradually, the innovative form replaced the old which lexeme (Ding 2022).
Functioning as the interrogative category of selection, or 'which', a 21 sɨ 21 is an adjective, placed after the head noun, such as ts h o 33 a 21 sɨ 21 ma 33 (people, which CLF) 'which person'. Due to its being used for another function, namely, the interrogative of manner, the which word a 21 sɨ 21 has changed its adjectival word class, and is used as an adverb in the how word, placed before verbs, namely, a 21 sɨ 21 mu 33 (how:do) or ha 21 mu 33 (how:do) 'how'. As a consequence, after the functional change, it is no longer acceptable to pronounce ha 21 ȵo 44 'how many/much' as *a 21 sɨ 21 ȵo 44 or a 21 sɨ 21 ma 33 'which one' as *ha 21 ma 33 in Adur Niesu. The irreversibility between ha 21 and a 21 sɨ 21 in the selection interrogative and the quantity interrogative suggests that ha 21 has become a different morpheme with different word class and different function from a 21 sɨ 21 'which', although it is derived from the which morpheme. The derivational path in Adur Niesu is proposed as below (see Figure 7 and also Ding 2022).

Tone Change in Prefixed Words
Tone change occurs to the prefixes a 33 -and i 33 -, which are used in the formation of property-denoting words, kinship terms, and animal words.

Tone 33 > 44/ _ 33 in Dimensional Words
This tone change is most popular in a 33 -/i 33 -prefixed property-denoting words in Adur Niesu.
The words in Table 17 are called stative verbs of dimensional extentives in Bradley (1995). In modern Adur Niesu, the positive dimensional words are prefixed by a 33 -, and the negative ones are prefixed by i 33 -, both sharing the same root. This derivational pattern is not productive in modern Nuosu and Niesu. However, historically, the positive and negative forms may have different roots, such as Nuosu a 44 lɨ 33 'heavy' and ʑo 44 so 33 'light', and Adur Niesu a 44 ʐɨ 33 'big' and ɛ 55 ʦɨ 33 'small'. According to Bradley (1995), the historical development is that the original negative dimensional words were replaced by forms that have the prefix i 33 -plus the positive dimensional words. The negative dimensional word 'small' in the big/small pair has persisted and has not been replaced by the i 33 -prefixed positive form in Nuosu and Niesu in Table 17. In the cases of 'heavy/light', while the replacement of the negative extentive forms by the positive forms occurs in Adur Niesu, the negative forms ʑo 44 so 33 (Shynra Nuosu), or i 33 so 33 (Yynuo Nuosu) 'light', have survived. But a different prefix ʑo 33 -, rather than i 33 -, is added to so 33 'light' in Shynra Nuosu (see Ding 2022).
It can be observed that this tone change spreads to all dimensional extentives in Adur Niesu, but not in Nuosu. This tone change is also related to the prefix a 33 -in other word formations besides the dimensional words. Although many of them have lost productivity, historically, it has several other semantic functions in Adur Niesu, including kinship terms, color words, and animal words. See Matisoff (2018) for a cross-linguistic study of Proto-Tibet--Burman *a-prefix.
In modern Adur Niesu, this tone change only has certain productivity in kinship terms and animal names, besides the dimensional words. Given names of Adur Niesu are mostly bisyllabic, such as ga 33 ko 33 , a given name often for female. One of the syllables of the given name can be taken and prefixed by a 33 -to express endearment with this tone change, such as a 44  'pigeon' f a 44 dʑɯ 33 'raven' g a 44 ɣo 33 'hoopoe bird' The a-prefix in color terms are lexicalized without any tone change, such as a 33 ni 33 'red, be red', a 33 t h u 33 'white, be white', a 33 nɛ 33 'black, be black', and a 33 ʂɨ 33 'yellow, be yellow'. If the tone change rules apply, the meanings will be changed. For example, the consultants indicate that a 44 t h u 33 , with the tone of the prefix raised to 44, means 'thick (e.g., book)' (see Table 17), but not 'white, be white' anymore.
Since Adur Niesu is SOV, if there is only one argument in the clause, it could be agent or patient. In some cases, the default context is clear to tell the meaning, such as xɯ 33 dzɯ 33 (meat eat) 'to eat the meat' as a non-reversible event. However, in many cases, ambiguity emerges. To disambiguate, other than the contexts, there are two main means to mark the patient of the clause.
First, the tone change of patient 33 > 44 / _ 33 is addressed. This tone change is on the patient. The argument is mostly monosyllabic personal pronouns before the main verb. The patient will change from tone 33 to tone 44. This strategy is often used when the main verb bears tone 33.  (60a) and (60b). With the tone change, the ambiguity in (60a) can be eliminated in (60b). Despite the ambiguity in (60a), it will often be understood, without the tone change, as a resultative construction 'someone stole his (belongings)' in Adur Niesu, where the patient is placed sentence initially as the topic and the rest the comment. 3 Due to the analytic morphology of Adur Niesu, there is the possibility that this tone change is caused by some floating tone marking patient. However, since we do not have any supporting evidence, it is synchronically an issue of tone change. If the monosyllabic arguments are replaced by polysyllabic ones, the tone change cannot apply. To disambiguate (61a), an analytic means by differential object marker ko 33 is used to mark the patient; see (61b). Similarly, since there is the way to disambiguate, (61a), without the marking, it will often be understood as 'dʑɛ 21 nɛ 33 stole su̠ 33 ga 55′ s (belongings)'. 61 a su̠ 33 ga 55 d ʑɛ 21 nɛ 33 k h u 33 . surname surname steal 'dʑɛ 21 nɛ 33 stole su̠ 33 ga 55′ s (belongings).' or 'su̠ 33 ga 55 stole dʑɛ 21 nɛ 33′ s (belongings).' b su̠ 33 ga 55 d ʑɛ 21 nɛ 33 =ko 33 k h u 33 . surname surname=DOM steal 'su̠ 33 ga 55 stole dʑɛ 21 nɛ 33′ s (belongings).' The differential object marker (DOM) can also be used with monosyllabic patients for disambiguation; see (60c). In this case, the tone change rule of patient 33 > 21 / _ ko 33 is applied. The citation tone 33 of the person pronoun will be lowered to tone 21; see (62).
The following pairs are only contrastive in the tone of the verb. If the original tone 21 is changed to 44, the meaning is also changed; see (64)

Tone Change in Reduplication for Interrogation
There are two rules for tone change to generate reduplication for yes-no interrogations: 33 > 44 / _ 33 and 21 > 33 / 21 _. It is clear that the two rules are consistently tone dissimilation, namely, adjacent same tones trigger dissimilation.
The first tone change, namely, 33 > 44 / _ 33, is productive in reduplicating monosyllabic verbs for yes-no questions; see (67). The first monosyllabic verb with tone 33 will rise to tone 44. See Figure 8 for the tone change. 67 a zɨ 33 + zɨ 33 → zɨ 44~z ɨ 33 'to buy or not' b ndo 33 + ndo 33 → ndo 44~n do 33 'to drink or not' c la 33 + la 33 → la 44~l a 33 'to come or not' d tɕo 33 + tɕo 33 → tɕo 44~t ɕo 33 'to turn or not' As was discussed in Section 3.6, on the surface, there seems to be a third rule of tone change regarding reduplication for interrogation: 55 > 21 / 55 _. However, the tone lowering from 55 to 21 is not a tone change, but the result of the floating tone associated with the interrogative particle a 21 after syllable reduction.

Effect of Floating Tone
Finally, the effect of the floating tone is discussed. On the surface, it appears to be a kind of tonal alternation. However, different from tone sandhi and tone change, it is the effect of the tone of an additional syllable after syllable reduction, such as tone 21 left after the reduced interrogative particle a 21 in Section 3.6.
Another case of floating tone is about tone 21 in Adur Niesu possessive pronouns. Tone 21 was originally borne by the Proto-Nuosu proper genitive marker *ni 21 . This genitive marker is reduced in Adur Niesu and Nuosu, but still kept in Yynuo Nuosu as ni 42 , such as a 33 p h u 33 =ni 42 t h ɯ 42 ʑɨ 33 (grandfather=GEN book) 'grandfather's book'. Lama (2022) reports the tonal change from Proto-Nuosu proper 21 to modern Yynuo Nuosu 42.

Conclusions
This study describes the segmental and suprasegmental phonology of Adur Niesu, a Loloish (or Ngwi) language spoken mainly in Liangshan, Sichuan, in southwest China. There are 41 phonemic consonants: nine plain plosives, three prenasalized plosives, eleven fricatives, four nasals, two laterals, nine affricates and three prenasalized affricates. Compared with Nuosu, a close dialect of Adur Niesu, it lacks voiceless nasals /m̥ / and /n̥ /. There are 10 monophthongs and one diphthong in Adur Niesu. A feature of Adur Niesu vowels is high vowel fricativization, occurring with the two high central vowels /ɨ/ and /ɨ̠ /, and the two high back vowels /u/ and /u̠ /. Adur Niesu's syllable structure is relatively simple. All are open syllables. The following segmental changes are reported: vowel lowering, vowel centralization, vowel assimilation, vowel fusion, consonant lenition, and aspiration of clanlects. It is common for Adur Niesu syllables to be reduced in continuous speech. There are three main types of syllable reduction: complete reduction including the segment and tone, partial reduction with a floating tone left, and partial reduction with the initial consonant left. There are three contrastive tones in Adur Niesu, namely, high-level tone 55, mid-level tone 33, and low-falling tone 21. There is also a sandhi tone 44. There are two types of tonal alternation: tone sandhi and tone change. Tone sandhi occurs at both the word and phrasal levels, and is conditioned by the phonetic environment; tone change occurs due to the morphosyntactic environment. Moreover, some seeming tonal alternation is the result of the floating tone after syllable reduction.
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Conflicts of Interest:
The authors declare no conflict of interest. It can refer to a grown-up animal, as long as it is some animal's offspring. 3 Adur Niesu resultative construction expresses the result happening to the affected entity, structured as affectee + instigator + complement clause, such as below. It does not follow the canonical SOV word order, but is construed in a topic-comment articulation. lɛ 21 bu 33 ts h ɨ 33 si 55 dzɯ 33 o 44 . cow:male 3SG kill eat PFV 'He killed the ox and ate (it).'