Here's why:
* "M" is pronounced the same in both languages.
* "a" is pronounced as a short "a" sound, similar to the "a" in "cat" or "hat."
* "d" is pronounced the same in both languages.
* "y" is pronounced as a short "ee" sound, like the "ee" in "see" or "tree."
Therefore, the closest French pronunciation of "Maddy" is "Ma-dee."