Last week in my class, we were discussing loanwords as well as semantic change. You couldn’t ask for a more perfect (although bothersome) news story incorporating these two aspects of linguistic change than this story about a bilingual promotional campaign in Canada for Vitaminwater, in which random English and French words were paired on the bottom of drink caps. But it all went horribly wrong when under one cap, the English word ‘you’ was combined with the French word ‘retard’ for ‘late’, as detailed in this article in the Province , and was then found by an Alberta family. Another cap had the perfectly ordinary French word douche ‘shower’. Coca-Cola (the parent company) has apologized profusely and cancelled the promotion (to its credit), and has said it was all a coincidence gone awry, although I still wonder whether it could be a rogue employee’s doing.
Learners of second languages are often warned to beware of ‘false friends’ – words that look like English words but in fact, in the other language, have a radically different meaning. Obviously ‘retard’ has a very specific and highly offensive meaning for most English speakers. But I’m a little surprised that, in the coverage of this story, there hasn’t been really any mention of the fact that ‘retard’ (with second-syllable stress) is not just a French word meaning ‘late’, but an English verb that, until recently at least, was in common use as a synonym for ‘delay’. Of course, these days the offensive connotation means that the verb ‘to retard’ is becoming increasingly rare, although it’s not hard to find plenty of examples from recent news articles. There is not a massive protest every time someone uses this verb in the customary way. This leads me to conclude that in fact, the real troublemaking word on the bottlecap is not ‘retard’ at all, but rather, ‘you’, which immediately turns the following word from … whatever it was, in English or French … into an insult. If the English word had been ‘kumquat’, I do not know whether we’d even have heard about this.
Glossographia 
At elder elevator doors in my country (Denmark), it is common that a red lamp has the label: “I fart”.
It translates to: “In motion” ; meaning that the elevator is moving.