Tone numbers are numerical digits used like letters to mark thetones of a language. The number is usually placed after aromanized syllable. There is no particular correlation to the actual pitch of the tone. Tone numbers are only defined for a particular language, or for a family of languages that share a common ancestor that had the set of tones indicated by the numbers, which are shared by the descendant languages.
Other means of indicating tone in romanization include diacritics,tone letters, and orthographic changes to the consonants or vowels. For instance, inMandarin, the syllable馬 (which has a falling-rising tone) is represented inWade-Giles romanization asma3, with a tone number; inHanyu Pinyin asmǎ, with a diacritic; and inGwoyeu Romatzyh asmaa, with a change in the vowel letter.
In the Chinese tradition, numbers, diacritics, andnames are assigned to the historicalfour tones (level, rising, departing, and entering) of Chinese. These are consistent across all Chinese dialects, reflecting thedevelopment of tone diachronically. In the later stage of Middle Chinese,voiced consonants (such as b-, d-, g-, z-) began to merge into voiceless ones (p-, t-, k-, s-) and such voiceless-voiced consonant contrast was substituted by further high-low pitch contrast (yin, and yang). It is also common to number the tones of a particular dialect independently of the others. For example,Standard Chinese has four–five tones and the digits 1–5 or 0–4 are assigned to them; Cantonese has 6–9 tones, and the digits from 0 or 1 to 6 or 9 are assigned to them. In this case, Mandarin tone 4 has nothing to do with Cantonese tone 4, as can be seen by comparing the tone charts of Standard Chinese (Mandarin),Cantonese, andTaiwanese Hokkien.
| Middle Chinese (and all modern Chinese languages) | ||||||||||
| Tone number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | ||
| Tone name | Yin level | Yang level | Yin rising | Yang rising | Yin departing | Yang departing | Yin entering | Yang entering | ||
| Modifier letter | ꜀ | ꜁ | ꜂ | ꜃ | ꜄ | ꜅ | ꜆ | ꜇ | ||
| Mandarin | ||||||||||
| Tone number | 1 | 2 | 3 | 4 | 5 or 0 | |||||
| Tone name | Yin level | Yang level | Rising | Departing | Neutral | |||||
| Tone letter | ˥ | ˧˥ | ˨˩˦ | ˥˩ | depends on context | |||||
| Cantonese | ||||||||||
| Tone number | 1 | 2 | 3 | 4 | 5 | 6 | 7 (1) | 8 (3) | 9 (6) | |
| Tone name | Yin level | Yin rising | Yin departing | Yang level | Yang rising | Yang departing | Upper yin entering | Lower yin entering | Yang entering | |
| Tone letter | ˥,˥˧ | ˧˥ | ˧ | ˨˩,˩ | ˩˧ | ˨ | ˥ | ˧ | ˨ | |
| Taiwanese Hokkien | ||||||||||
| Tone number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |
| Tone name | Yin level | Yin rising | Yin departing | Yin entering | Yang level | Yang rising[1] | Yang departing | Yang entering | High rising[2] | Neutral |
| Tone letter | ˥ | ˥˩ | ˧˩ | ˧ | ˨˦ | ˨ | ˧ | ˥ | ˧˥ | depends on context |
Note:Tone sandhi rules and the unstressed syllable of Mandarin are not listed here for simplicity.
To enhance recognition and learning, color has also been associated with the tones.[3] Although there are no formal standards, thede facto standard has been to use red (tone 1), orange (tone 2), green (tone 3), blue (tone 4) and black (tone 5). This color palette has been implemented in translation tools[4] and online dictionaries.[5]
Although such numbers are useless in comparative studies, they are convenient for in-dialect descriptions:
Someromanization schemes, likeJyutping, use tone numbers. Even forPinyin, tone numbers are used instead whendiacritics are not available, as in basicASCII text.
For the numbers of the traditional tone classes, which are consistent between dialects, seefour tones in Middle Chinese.