Whenever a waiter gives him a half-full glass of wine, a friend of mine always retorts: "Man, fill this glass up. My nose won't drown in the wine. I am not a white man."

I don't mind when he makes the remark to a black waiter, even in the presence of our white friends, or, indeed, in the presence of his wife, who is of Caucasian persuasion.

But I do get worried when he makes the remark in the presence of white strangers, who might mistake him for a humourless racist.

In a racially sensitive country such as South Africa, one does need to be careful about the kind of ethnic jokes or remarks that one makes.

The case of a guy in Klerksdorp in May 2005 who allegedly killed another who called him a Shangaan is instructive.

Over the years, and because they are in the minority, Shangaans have been the butt of many bad jokes.

It's been said they are stupid and have no fashion sense (they are said to wear green shirts, yellow trousers and red shoes).

Which, of course, is a sad and painful generalisation if you consider that there are many South Africans of Shangaan extraction who are brilliant businessmen, academics and entertainers.

There's Jomo Sono, Chicco Twala, Irvin Khoza, writer and academic Chabani Manganyi.

But in the face of such evidence to the contrary, you still get people who refer to an inferior form of polony or sausage sold in the townships as "Shangaan wors".

Therefore, if a person calls you a Shangaan, it's considered the height of insolence - especially if you are not Shangaan.

Ethnic stereotypes are not the preserve of black socialisation. English and Afrikaans people have stereotypical barbs they use on each other: rooinek, rock spider, limey, pommy etc.

In the case of black South Africa, with the possible exception of those in Johannesburg, which has always been a melting pot, black people from different ethnic groups didn't, over the years, know each other's languages and cultures. This was simply because they couldn't interact across ethnic lines.

This, therefore, became a breeding ground for many acerbic ethnic insults and stereotypes.

Zulus were dismissed as warlike and stupid. And, yes, the assumption that Zulu is a language of aggression still persists.

A few weeks ago, during a session in the National Assembly, when Lechesa Tsenoli lost his patience with members of the EFF he resorted to Zulu: "Uyabona-ke manje seniyedelela!" (You see now, you're being insolent.).

He thought he was driving the fear of God into the EFF. He did the opposite. For more than five minutes, the House came to a standstill. Tsenoli was being asked to withdraw the word "delela". And guess what: a few days later, they were selling T-shirts with the words Delela! The Delela video has gone viral.

Had Tsenoli tried to control the EFF using his mother tongue SeSotho, I doubt if there would have been such a furore in the House.

And, the Nkandla imbroglio has not helped at all: in the eyes of many, it is proof of Zulu stubbornness. In the face of mounting evidence to the contrary, the man in question still doesn't concede any wrongfulness in the entire saga.

In terms of the stereotypes that I was going on about, Sothos were, at the height of apartheid, considered cowards who spied on their black brethren on behalf of white bosses at the mines and factories. Tswanas were stingy and mean-spirited (in ancient times they drowned themselves than give the enemy the pleasure of beating them up).

Swazis, like Tswanas, also couldn't fight to save their lives. All they could do was insult their enemies "until they stank".

Friday was known as Boesman's Christmas because of the perception that coloured people spent their money on delicacies and booze come Friday, which was payday, and were dirt poor by Monday.

When Zulu people want to tell you how pitifully inebriated you are they say: "udakwe njengeNdiya elingenabhizinisi - you're as drunk as an Indian who has no business" (this, of course, is based on the observation that serious Indians who run businesses - mostly Muslims - do not drink).

In any society that is strong on stratifying people according to race, those at the bottom layer tend to be vicious with each other.

With the demise of apartheid, we have begun to realise ethnic stereotypes as exactly that: stereotypes not backed by fact. We have discovered our shared humanity, thank God.

Jokes can be a measure of a people's sense of maturity and sophistication. In other words, it's healthy to laugh at oneself.

If you can't laugh at yourself, then the outsiders will laugh at you. And it's painful when you get laughed at by "the other".

I hate it when those Americans make jokes about our president, but I don't mind if the joke is from Trevor Noah or David Kau. Msholozi is ours, dammit. We reserve the right to put a showerhead on his head.

Go and create your own Nkandla and make fun of it, you tjatjarag Americans.

* Comments: fredkhumalo@post.harvard.edu