The Ryukyu island arc span the southwestern parts of Japan, straddling the boundary between the East China Sea and the Pacific Ocean, from around Taiwan to Kyushu. It is this island chain in which we will find Japan’s westernmost inhabited island, at just 108km to Taiwan’s east, which goes by the name of Yonaguni-jima, or 与那国島. In fact, the westernmost point of Japan can be found in Cape Irizaki on this very island.

Census data puts the island’s population at around 2000 people, with three main towns, Kubura, Higawa, and Sonai. However, as the addresses there would suggest, these towns are collectively administered under the town of Yonaguni, in the district of Yaeyama. Some residents of the island still speak the Southern Ryukyuan language called Yonaguni, or Dunan Munui.

Like Miyakoan, we do not really precisely know how many native speakers of Dunan Munui there are, possibly due to its treatment as a Japanese dialect rather than a separate language by the Japanese government. However, Dunan Munui is not mutually intelligible with Japanese, or is it mutually intelligible with other Ryukyuan languages. The Yaeyama language could be argued as its closest cousin.

But what is known is, younger generations tend to be monolingual in Japanese, meaning that intergenerational transmission of Dunan Munui is limited to some extent. In fact, most speakers are now older adults, and are bilingual in Standard Japanese. Browsing through the literature covering its vitality on the Endangered Languages Project website, the general consensus seems to be that Dunan Munui has fewer than a thousand native speakers, and is classified as an endangered or a severely endangered language. The most recent estimate, taken in 2015, puts the number of native speakers of Dunan Munui at around 400, or a quarter of the island’s population estimate of 1600 residents.

Unlike Japanese and some Ryukyuan languages, Dunan Munui distinguishes 3 phonemic vowels, /a i u/, in contrast to the 5-vowel system in Japanese, /a i u e o/. However, these vowels may display allophonic variation. In a 2015 overview of Dunan Munui grammar, Yamada, Pellard, and Shimoji mentioned the occurrence of the /o/ vowel in interjections and do, an exclamative particle which occurs at the end of the sentence. These vowels are not phonemically distinguished by length as well.

This vowel inventory is complemented by 17 consonants, in which plosive consonants have three distinct series, which are called the fortis, lenis, and voiced plosive consonants. Lenis plosive consonants occur as aspirated voiceless consonants, while fortis plosive consonants occur as unaspirated and tense voiceless consonants. Unlike ‘k’ and ‘t’ however, the ‘p’ consonant does not have a lenis counterpart. These sounds are organised into syllables, in which the most complex structure possible being CGVVN, where C is a consonant, G is a glide /j/ or /w/, V is a vowel, and N is a nasal consonant, usually /n/. However, it is possible for this nasal consonant to occur at the start of the word, like nda (you). There are also three kinds of word accents documented in Dunan Munui, the high, the low, and the falling tones, though an earlier publication by Uemura in 2003 mentioned four, with the fourth one being the rising contour.

Linguists have identified several salient sound correspondences between Dunan Munui and Japanese, such as the /d/ sound in Dunan Munui corresponding to the /j/ sound in Japanese, which we can already infer by comparing Dunan Munui with the word Yonaguni. There is also the correspondence of the Dunan Munui /b/ with the Japanese /w/, Dunan Munui /g/ with the Japanese /k/, and the Dunan Munui /ŋ/ with the Japanese /g/, especially in between vowels.

In Dunan Munui grammar, perhaps one notable difference from Japanese is the way verb negation occurs. Dunan Munui distinguishes between stative verbs and other verbs, the former being used to indicate a state of being or perception (e.g. to be low). Negation uses -anu for most verbs, and -minu for stative verbs. Meanwhile, adverbs may be formed from stative verbs using the suffix -gu. Differences also occur between case particles in Dunan Munui and Japanese, with the terminative being =ta in Dunan Munui, and made in Japanese. Yes/no questions are formed using the sentence-final particle na, and the main honorific marker is a verb, warun.

This language is also behind the name given to an interesting set of characters called the kaidā glyphs, which are a set of pictograms that used to serve the function of communicating the type and quantity of a certain type of goods to be paid as poll tax or tribute by the island’s residents. While not considered to be a full-fledged writing system, kaidā glyphs developed as a means to communicate and record quotas for goods and objects levied upon the residents of the Yaeyama islands. Literacy in the Yaeyama islands, like many remote islands in the region, was low back in those days, and so necessitated the development of such glyphs to notify the commoners who would not have been able to read the style of administrative written Japanese used in the centuries past. Today, however, these kaidā glyphs are more often found as artistic expressions rather than its original purposes.

The overall status of documentation of the Yonaguni language is concerning. Bilingual lexicons of the language are mostly published for the Dunan Munui – Japanese language pair, and no full-fledged dictionaries are published thus far. Additionally, with the ongoing research in the pitch-accent system of Dunan Munui, this documentation may or may not include accent marks for Dunan Munui words. Further work is still needed to better understand its syntax and tone system as well.

Further Reading

Ikema, N. (2003) ‘Dictionary of the Yonaguni language’, Yonagunigo jiten.

Izuyama, A. (2012) ‘Yonaguni’, in (ed. Tranter, N.) The Languages of Japan and Korea, Routledge, pp. 412-457.

Uemura, Y. (2003) ‘The Ryukyuan Language’, in Endangered Languages of the Pacific Rim, translated by W. P. Lawrence, Tokyo, Ministry of Education.

Uwano, Z. (2011) ‘Materials of the word prosody of the Yonaguni dialect (2)’, NINJAL Research Papers, 34, -pp. 135-164.

Yamada, M., Pellard, T. & Shimoji, M. (2015) ‘Dunan grammar (Yonaguni Ryukyuan)’, in Handbook of the Ryukyuan languages: History, structure, and use, De Gruyter Mouton, pp. 449-478.