The five most common Cantonese profanities, vulgar words in the Cantonese language are diu (屌/𨳒), gau (㞗/鳩), lan (𨶙𡳞/撚), tsat (杘/柒) and hai (屄/閪), where the first literally means fuck, “Diu” (or Jiu) is literally the word for Penis. while the rest are sexual organs of either gender. They are sometimes collectively known as the "outstanding five in Cantonese" (廣東話一門五傑). These five words are generally offensive and give rise to a variety of euphemisms and minced oaths. Similar to the seven dirty words in the United States, these five words are forbidden to say and are bleep-censored on Hong Kong broadcast television. Other curse phrases, such as puk gai (踣街/仆街) and ham gaa caan (咸家鏟/冚家鏟), are also common.
Diu (traditional Chinese: 屌 or 𨳒 ; Jyutping: diu2), literally meaning fuck, is a common but grossly vulgar profanity in Cantonese. In a manner similar to the English word fuck, diu expresses dismay, disgrace, and disapproval. Examples of expressions include diu nei! (屌你！ or 𨳒你！, fuck you!), and the highly offensive diu nei lo mo! (屌你老母 or 𨳒你老母, fuck your mother) or diu nei lo mo chau hai! (𨳒你老母臭閪, fuck your mother's foul cunt).
The word diu was originally a noun meaning the penis and evolved as a verb. Regarded as a grossly vulgar word in Cantonese, the word has gained a new meaning in Taiwan to refer to "cool". In this context, the Mandarin pronunciation may not be censored on TV broadcasts but the original Cantonese pronunciation is still taboo.
Certain euphemisms exist, including siu (小) (small/little), tsiu (超), yiu (妖) 
The phrase 戇𨳊 ngong6 gau1 is an adjective that may be loosely translated as a "dumbass". Minced variants include 戇居 ngong6 geoi1, 戇Q ngong6 kiu1, 硬膠／硬胶 ngaang6 gaau1 (lit. hard plastic) and "on9" (used in internet slang). The phrase mou4 lei4 tau4 gau1 (無厘頭尻) meaning "makes no sense" was cut to mou4 lei4 tau4 to avoid the sound gau1. Similar to "fucking" in English, this word is usually used as an adverb. Compare this:
- 黐線 (crazy)
- 黐㞗線 (fucking crazy)
Two common euphemisms gau, which only differ in the tone, include 九 gau2 (nine) and 狗 gau2 (dog, but it may change the original "dumbass" meaning into "cunning" instead).
Euphemisms includes 懶 laan (lazy) or 能 nang (able to).
Tsat (杘 or 𡴶 or Chinese: 𨳍; Jyutping: cat6), sometimes idiomatically written as 柒, is a vulgar word for an erect penis. Its American English equivalent is "boner". Ban6 cat6 (笨杘) (stupid dick) is a more common phrase among others. However, it is usually used as a vulgar adjective especially among the youth. It means "ugly" or "shameful".
cat6 tau4 (杘頭 or 𡴶頭 or 柒頭) can be loosely translated as "dickhead".
A common euphemism is 七 cat1 (seven), which only differs in the tone. Other euphemisms include 刷 caat3 (to brush) and 賊 caak6 (thieves). As a result, thieves that are easily caught by the police are often intentionally described as 笨賊 ban6 caak6 (stupid thieves) in the newspaper to achieve the humorous effects from the phrase ban6 cat6.
Hai (traditional Chinese: 屄 or 閪 ; Jyutping: hai1) is a common vulgar word that literally means vagina. The English equivalent is "cunt". 屄 is more common on the mainland of China, with 閪 being used in Hong Kong and Macao. The Chinese character 屄 consists of two parts: the upper part is 尸 that means "body" while the bottom part 穴 means "a hole". The Chinese character thus literally means a "hole at the bottom of the body". Two common phrases include 傻閪 so4 hai1 (silly cunt) and 臭閪 cau3 hai1 (stinking cunt). Also another phrase is 𨳒閪 diu2 hai1 (fuck a pussy).
A common euphemism is 西 sai1 (west). The phrase 西口西面 sai1 hau2 sai1 min6 (west mouths and west faces) is often used to describe women who have an impolite look. Some words that are associated with western culture such as 西人 sai1 yan4 (Westerners) may become Cantonese jokes that base on the ambiguity of these vocabularies. Other euphemisms include 鞋 haai4 (shoes) and 蟹 haai5 (crabs). As a result, crabs are sometimes intentionally linked with other words such as stinking and water to achieve some vagina-related humorous effects.
The word hai can also mean total failure as in the phrase hai1 saai3 (閪晒). The Chinese character 晒, which in Cantonese is the verbal particle to stress an action. To further stress the failure, sometimes the phrase hai1 gau1 saai3 is used (the word gau that means penis is put in between the original phrase). Since this phrase is highly offensive (it consists two of the five vulgar words), a euphemism or xiehouyu, a kind of Chinese "proverb", is sometimes used. As in a normal xiehouyu, it consists of two elements: the former segment presents a scenario while the latter provides the rationale thereof. One would often only state the first part, expecting the listener to know the second. The first part is "a man and a woman having a sunbath (naked)" (男女日光浴). Since the penis and vagina are both exposed to the sun, the second part is hai1 gau1 saai3 (閪𨳊晒) — a pun for total failure. Therefore, if one wants to say that something is a total failure, he only has to say 男女日光浴, and the listener will understand the intended meaning.
Other curse phrases
Puk gai (踣街, usually idiomatically written as Chinese: 仆街; Cantonese Yale: puk1 gaai1) literally means "falling onto street", which is a common curse phrase in Cantonese that may be translated into English as "drop dead". It is sometimes used as a noun to refer to an annoying person that roughly means a "prick". The phrase can also be used in daily life under a variety of situations to express annoyance, disgrace or other emotions. Since the phrase does not involve any sexual organs or reference to sex, some argue that it should not be considered as profanity. Nevertheless, "PK" is often used as a euphemism for the phrase. The written form can be seen on graffiti in Hong Kong and in Guangdong.
In Southeast Asia, the meaning of the phrase has evolved so that it is no longer a profanity, and is usually taken to mean "epic fail". In Taiwan, it is commonly used to refer to planking. The term is even used in a colloquial sense by Malaysian Malays, in which case it is usually rendered as "pokai".
Ham Gaa Caan
Ham6 gaa1 caan2 (Chinese: 咸家鏟 or Chinese: 冚家鏟; Jyutping: ham6 gaa1 caan2) is another common curse phrase in Cantonese that literally means "may your whole family be bulldozed". 鏟 caan2 means to bulldozed, which possibly relates to a funeral and ultimately to the meaning of death. Like puk6 gaai1, the phrase can both be used to mean "prick" or to express annoyance, but many find ham gaa caan much more offensive than puk gaai, since the phrase targets the listener's whole family instead of just himself.
咸家伶 or 冚家拎 Ham6 gaa1 ling1, 咸家富貴 or 冚家富貴 ham6 gaa1 fu3 gwai3 (may the whole family be rich), 咸家祥 or 冚家祥 ham gaa ceong (may the whole family be fortunate) are common variant but 拎 ling (to take/carry something) has little logical relations with the original phrase. Adding the words ham gaa (whole family) in front of a bless can actually reverse the meaning. The appropriate word for "the whole family" is 全家 cyun gaa to avoid any negative meanings.
In Hong Kong, there are specific by-laws that forbid the usage of profanity in public. For instance, it is not permitted to "use obscene language … in Ocean Park", for which "an offence is liable on conviction to a fine at level 1 and to imprisonment for 1 month", while in the MTR, it was prohibited to "use any threatening, abusive, obscene or offensive language …." until 2017.  However, despite the explicit prohibition by various laws, the exact definition of "obscene language" is not given in the ordinance.
Notes and references
- Pang, 3.
- Pang, preface.
- Pang, 7.
- Pang, 116-117.
- Pang, 29.
- Pang, 108.
- Pang, 102.
- Pang, 109.
- "Curse phrase dictionary" (in Chinese). Cantonese Profanity Research Site. Archived from the original on 2008-02-17. Retrieved 2008-02-08.
- Pang, 55.
- Pang, 56.
- Ocean Park Bylaw (Cap. 388B) § 5, "Conduct of public".
- Mass Transit Railway By-laws (Cap. 556B) § 28H, "Abusive language".
- "Legal issues of using obscene language" (in Chinese). Cantonese Profanity Research Site. Archived from the original on 2008-01-11. Retrieved 2008-02-07.
- Robert S. Bauer and Paul K. Benedict (1997). Modern Cantonese Phonology. Berlin and New York: Mouton de Gruyter. ISBN 3-11-014893-5. Part of the chapter 3 concerns Cantonese profanity.
- Kingsley Bolton and Christopher Hutton, "Bad boys and bad language: chou hau and the sociolinguistics of swearwords in Hong Kong Cantonese", in Grant Evans and Maria Tam ed. (1997). Hong Kong: the Anthropology of a Chinese Metropolis. Richmond, Surrey: Curzon. ISBN 0-7007-0601-1.
- Pang, Chi Ming (2007). Little Dogs are too Lazy to Polish Shoes (小狗懶擦鞋): a Study of Hong Kong Profanity Culture (in Chinese). Hong Kong Subculture Publishing. ISBN 978-962-992-161-3.