Although there is a degree of overlap with schist’s discussion of Taiwanese tone numbers, I think it’s worthwhile to add a brief discussion of tones in Cantonese.
Whether, as a student of Cantonese, you’re approaching the language from a more technical, academic standpoint, or from a more casual ‘business-trip’ standpoint makes a difference in how you’d want to think about tones in Cantonese. Technically, Cantonese has nine tones (and debatably even eleven); if you are a gwailo looking to become conversational, you can pretend there are only six. If your first language is non-tonal, then good luck trying to distinguish five or more.
Let’s consider all nine. The nomenclature for the tones is identical (in terms of characters at least) to the list for Taiwanese above. Below are the Cantonese pronunciations of them (in the order of the first list):
1. yam ping—high level tone
2. yam seung—mid rising tone
3. yam heuy—mid level tone
4. yam yap—high level (entering)
5. yeung seung—low rising
6. yeung ping—low level
7. yeung heuy—low falling
8. yeung yap—low level (entering)
9. jung yap—mid level (entering)
The 9th tone, “jung yap”—zhong ru, or ‘middle entering’ in Mandarin—is found only in the Cantonese (or Yue dialects). In other dialects 9 and 4 are indistinguishable.
Ramsey (1987) makes note of two extra tones in Cantonese, “changing tones”, which are found only in colloquial usage, and replace the standard tone of a word which has a common everyday, usage. The first of these tones has a high level pitched and is marked by a degree sign. The second is usually marked by an asterisk and has a “long high rising pitch.”
If this all seems like it would be impossible to distinguish aurally, don’t worry, it is. Even the average native speaker, if asked, will probably only be able to think of seven tones at most. Departing (heuy, above) and entering tones of the same pitch are practically indistinguishable; and according to this idea most practical Cantonese primers and even input modules for computers, reduce the number of tones to six. This should probably be the goal for a student to try and reproduce if they want to be clearly understood: high level (1), mid rising(2), mid level (3), low falling (7), low rising (5), low level (6). Depending on the text or instructor though, your results may vary.
Cantonese romanization is a minefield: it is not uncommon to pick up five different texts and find a different style in each of them, especially in non-academic primers. The same goes with tone-representation —Cantonese is not a book-printer’s friend. The most commonly used system is the Yale system. Tone representation in the Yale system is a mix between the diacritical marks in pinyin and the spelled-in method of Gwoyeu Romatzyh. Diacritics determine the pitch change (rising is an acute accent, falling is grave, and no mark for level) and the letter ‘h’ is inserted after the vowel to indicate low pitch. Therefore if you saw the word fahn, it would be low level, while fa`n would be high falling.
I found a rather unique (and confusing) system of tone marking in the casual primer “Teach Yourself Cantonese” by H. Baker and P.K. Ho. These authors distinguish seven tones: high level, high falling, mid rising mid level, low falling, low rising, low level. Furthermore they mark pitch change (rising, falling, level) with the normal diacritics, but represent high tones by putting an ‘h’ before the vowel, and low tones by putting an ‘r’ before the vowel. One used to reading the Yale system would see the h’s here and read the word with the opposite tone. I mention this, not because this is a common system by any means, but to show that one can run into some very exotic varieties of romanization where Cantonese is concerned.
Baker, H. and P.K. Ho. 1996 "Teach Yourself Cantonese". Chicago: NTC Publishing.
Liu, V. and J. Dorra. 1994. "Let's Talk: Cantonese". San Francisco: JBD Publishing.
Ramsey, R. 1987. "The Languages of China". Princeton, NJ: Princeton Univ. Press.