There's a cave in Vietnam which has been newly opened to tourism called Hang Sơn Đoòng (English Wikipedia article here).

My question is about the syllable in the name of the cave which is represented as đoòng. I didn't think the orthography allowed a nucleus written as oo, but it's there in the Vietnamese version of the page as well.

Also, the only matches for đoòng that I can find are references to the cave. Is this a possible nucleus in Vietnamese orthography, and if so, what does it represent?

3 Answers 3


It is a licit nucleus, transcribed -ɔŋ in Nguyen-Dinh Hoa's Vietnamese-English Dictionary (1966), Charles E. Tuttle Company. In the Hanoi dialect, it rhymes with the nucleus -on, but having a different coda. But quickly looking through the same dictionary, I can't find any examples, so I'm supposing it's infrequent.

I did just find one, the French loan boong < pont "deck of a ship."

  • Thanks for your answer. It's strange, though, since <o> usually renders [ɔ]. I wonder if this is a remnant of some pre-reform orthography.
    – jogloran
    Commented Sep 15, 2013 at 12:42
  • @jogloran my understanding of the choice of spelling is that orthographic velars are pronounced as labial-velars following orthographic round vowels. in such a case the vowel itself is usually realized as a labializing diphthong. in southern dialects, which have coda mergers, you could get right pronunciation with the spelling bon, without resorting to the doubled vowel.
    – user483
    Commented Sep 17, 2013 at 1:50
  • Right, so in other words, bong would be rendered akin to [ɓawŋm] while boong is invariably [ɓɔŋm]?
    – jogloran
    Commented Sep 17, 2013 at 3:22
  • @jogloran yes, except i would guess that boong wouldn't have a labialized coda.
    – user483
    Commented Sep 17, 2013 at 23:56
  • 1
    you can find more examples in Wiktionary, I've just added some in my answer Commented Sep 13, 2014 at 5:08

I'm no linguistics expert but the sound "oong" in the North is pronounced like "on" /ɔŋ/ in Southern dialect. In the South they are both pronounced the same.

For example the word "đoòng" above is pronounced as "đòn" in Southern Vietnam. Some other common words for this are "xoong nồi" (pot for cooking), "cải xoong (Nasturtium officinale/Nasturtium microphyllum, a type of vegetable)," "boong tàu" (ship deck), "xe goòng" (wagon), "boong-ke" (from German bunker with french pronunciation)...

  • I see you answer some question about Vietnamese. It may be good to open a Vietnamese Language Q&A in stackexchange: area51.stackexchange.com
    – NoName
    Commented Feb 8, 2016 at 6:40

I think the best way to make the distinction is that: - 'ong' should be rendered as either [awŋm] or [oŋm]. - 'oong' should be rendered as either [awŋ] or [oŋ]. So the difference is in fact the bilabial nasal. The same phenomenon appears in the following pair 'ông' vs dialectal 'ôông'


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.