Chinese tone marks and which vowel they go on

[pne]

(Mostly for my own personal reference)

I was wondering what the rule was as to which vowel takes the tone mark in Pinyin transcription; I seemed to recall that there was an ordering of the type "if there's an A in the syllable, it gets the tone, else if there's an ..." but then was confused because I felt that syllables such as duì and liú should both get the accent on the final letter, yet they both consist of the vowels I and U.

I found an answer in this page on Chinese pronunciation (at the bottom):

9. Tone marks are written above the main final of a syllable. The main final can be identified according to the following sequence: A-O-E-I-U-u. For example, in “AO”, the main final is “A”; in “IONG”, the main final is “O”. When “I” and “U” are combined into a syllable, the tone mark is written above the second final: “liu”, “shui”.

(In the transcription that page uses, apparently, U = Pinyin "u", u = Pinyin "ü".)

Other useful pages:

• A Pinyin-to-GR [Gwoyeu Romatzyh] conversion table (Other GR stuff on that site:
  • GR Junction
  • PY to GR conversion table (complete syllables)
  • GR to PY conversion table (complete syllables)
  )
• A conversion chart bopomofo-Hanyu Pinyin/Tongyong Pinyin/Wade-Giles (illustrating nicely the way codas are written depending on whether they have an initial or not, e.g. wen/un, weng/ung, wei/ui)
• A similar chart
• And another one (this one also has a list of syllables at the end—presumably, all possible syllables are enumerated)

(That reminds me: I thought I remembered a chart in plain text form which had Pinyin, Gwoyeu Romatzyh, Yale, and an example hànzì for all possible syllables. I don't know where I got it from, though. Anyone have any idea?)

Incidentally, this confirmed what I had previously suspected: that zhongwen.com does not correctly position its tone marks for all syllables; for example, it has dùi, líu, and xíong instead of the correct duì, liú, and xióng.