Yann LeCun is called Yann Le Cun [0] in French, but "Le" and "Cun" are smashed together in English. Lafayette [2] is of course called La Fayette [3]. Du Pont becomes DuPont, and so on.
[0] https://fr.wikipedia.org/wiki/Yann_Le_Cun
[1] https://en.wikipedia.org/wiki/Yann_LeCun
[2] https://en.wikipedia.org/wiki/Gilbert_du_Motier,_Marquis_de_...
[3] https://fr.wikipedia.org/wiki/Gilbert_du_Motier_de_La_Fayett...