It’s easy to make up French words. I do it all the time when I can’t think of the exact one I want. I simply Frenchify the English word I’m thinking of! Sometimes it works, sometimes it doesn’t.
However, there are certain rules for making up French slang. It’s known as verlan. It changes existing French words into new ones by switching around the syllables, or reading them backwards. French for ‘backwards’ is ‘envers’, and that’s where ‘verlan’ comes from, with an ‘l’ added in the middle. The spelling can be changed a little to reflect the pronunciation.
There are a few different ways to make verlan. When a word has two or three syllables, the second one is put first. For example, ‘bizarre’ becomes ‘zarbi’ and ‘cigarette’ becomes ‘garetci’. On that basis , ‘llama’ would be ‘mala’, and ‘alpaca’ would be ‘calpa’.
For a one syllable word, there’s a bit more cunning involved. If a word has a silent ‘e’ at the end of it, as in ‘moche’ (ugly), then you pronounce it before you make up your verlan word. So ‘poule’ becomes ‘lepou’. If the word doesn’t end with a silent e, then you add one. ‘Foot’ (football) turns into ‘tefoo’.
It starts to get very complicated after that. If a verlan word ends in a vowel, that’s usually cut off, for example. And there’s also reverlanisation, double verlanisation and incomplete vernalisation. I think a grasp of the basics is enough for now!
I got interested in verlan after hearing my kids come out with words like ‘rempas’ (= parents) and ‘béton’ (= tomber, as in ‘laisse tomber’, forget about it). I dug around and found out about it.
(If you’re interested in slang and less mainstream French in general then you should get a Kindle version of Talk Dirty French by Alexis Munier and Emmanuel Tichelli. Very informative!)