Combien de mamans a votre fils?
Trans.: How many mommies does your son have? — La cage aux folles (1978 French comedy film, originally a 1973 French play; afterward, The Birdcage, 1996, an American remake.)
This joke is all about context: A conservative man has just discovered that the parents of the young man his daughter wants to marry have deceived him by presenting two different people as the youth's mother. Little does he know, but one of the mothers is a cross-dresser.
Mon garçon, ton grand-père a vécu dans les collines de l’Autunois ces soixante-dix ans, mais je peux pas te expliquer le passé composé.
Trans.: My boy, your grandfather has lived in the hills of the Autunois for these seventy years, yet I cannot explain to you the passé composé. — After a 1970s New Yorker cartoon
For all I know, this New Yorker cartoon caption was taken from a French cartoon, but I only saw it in English, and, knowing the New Yorker's proclivity for erudite humor, I suspect it was not originally published by the French.
J’ai perdu mon travail. En fait, j’ai PERDU pas mon travail. Je sais où le trouver. Mais quand j’y vais, quelqu’un d’autre fait le travail.
Trans.: I lost my job. Actually, I didn’t LOSE my job. I know where it is. But when I go there, someone else is doing it. — After comic Robert “Bobcat” Goldthwait
I translate this joke for no particular reason other than that I like it and wanted to see how it might look in French. The joke may not translate because it is based on the ambiguous concept of losing something by having it taken away versus not knowing where it went. A native French speaker might be needed to determine the best way to convey both meanings. Notice that I use the exact same verb twice in the French version but two different forms of the verb in the English version.