Tone name
Tones in Chinese derive from the traditional Middle Chinese tone classes, known as Ping Sheng (平聲), Shang Sheng (上聲), Qu Sheng (去聲), and Ru Sheng (入聲), which in English in the linguistic literature, are sometimes called the level, rising, departing and entering tones. The Ru sheng characters derive from characters in Middle Chinese which end in -p, -t or k.
In modern dialects, characters which derive from these four Middle Chinese tone classes may be split into two registers, yin (陰) and yang (陽), sometimes they have been termed upper and lower registers respectively, although this may be a misnomer, as some dialects having yin splittings may exhibit a tone pitch which is lower, and conversely, the yang register may exhibit a higher tone pitch.
So, when the four tone classes split, we form eight tone types,
Yin Ping, Yang Ping, Yin Shang, Yang Shang, Yin Qu, Yang Qu, Yin Ru and Yang Ru.
Cantonese has a further splitting of the Yin Ru tone, thus exhibiting 9 tones. Other dialects like Hakka have a merged Shang tone as does Mandarin. There are some dialects which have a complex set of tone splittings, and yin and yang are thus insufficient to cover these exceptional cases.
Vietnamese is another tonal language. The standard Vietnamese pronunciation is based upon the speech of northern Vietnamese Tonkin basin speakers.
It has six tones, known as, ngang (or bằng), sắc, huyền, hỏi, ngã and nặng tones. The tones are described as being mid level, high rising, low falling, low rising, high creaky (or broken), and low creaky in relation to their pitch levels respectively.
However, in the south of Vietnam, there is a merging of the hỏi and ngã tones, in effect leaving five basic tones.
With regard to the creaky or broken tones, these are low pitch often with a glottal stricture during the pronunciation of the syllable.
