Jyutping spells Cantonese in Latin letters, and its tone numbers must never be superscript
Cantonese has nine tones, yet Jyutping, the Hong Kong romanisation scheme from 1993, marks them with just six plain digits. Its creators even issued a notice insisting those digits stay ordinary numerals, not tiny superscripts. The system now ships built into Apple devices, and some people write Cantonese entirely in it.
The Linguistic Society of Hong Kong devised Jyutping in 1993. Its name is itself written in the system and squeezes together the first syllables of the Cantonese words for the Cantonese language, jyut6 jyu5, and for a phonetic alphabet, ping3 jam1, the same term Mandarin speakers know as pinyin. Although it was built to show pronunciation, it has also been used to write Cantonese as an alphabetic language in its own right.
About a dozen romanisations came before it, going back to Robert Morrison's pioneering scheme of 1828 and including the popular Yale and Sidney Lau systems. Jyutping broke with all of them. It brought in z and c as initial consonants, used eo and oe inside finals, and swapped the y that every earlier system used for j. Compared with Yale, it also has five finals Yale lacks, found in colloquial words, and it relies purely on tone numbers where Yale traditionally uses accent marks plus the letter h. A 2018 revision added two finals, -a and -oet, the latter useful for sounds like belching or snoring.
Tones are the tricky part. Cantonese has nine of them spread across six contours, but three are entering tones that only occur in syllables ending in p, t or k, so Jyutping folds them into the six numbers. Learners sometimes memorise a sentence meaning that feng shui says we will prosper, whose syllables run through the tones in order. The society's guidance says superscript or subscript digits make the tone harder to read, although bold or colour are acceptable, in contrast to Sidney Lau and Wade-Giles, which do raise their numbers.
Typing is where many people meet it. Jyutping input methods let users type a syllable and pick from matching characters. Since macOS Ventura and iOS 16, Apple has included it as a standard keyboard for traditional characters.
Source: Jyutping
