French first names are rarely shortened or changed to nick names. Christophe is not Chris, Valerie not Val and Thomas not Tom. They take a pride in their full title; Marie-Louise, Jean- Claude or Louis-Henri.
Unlike the UK & US, where Bill & Bobs, Ron and Rob, Marty & Matt, Pam & Pat, abound. English first names are less traditional, changed by fashion, influenced by celebrities or fiction. Not in France the Kylies (Minogue), Harry (Prince or Potter), Wayne (John or Rooney), Johnny (Depp or Halliday). Neither do they intentionally invent or spell names differently; no Corrie-Lea, Kristofer or Zandras.
Granted they have David (Beckham or Bowie), Sylvestre ( Stalone) and Henry (Thierry or King), but it’s because they are traditional names. Names like Jean, Baptiste, Claudine or Virginia. In fact every day of the year is dedicated to a different saint’s name. These names are not just listed as a religious acknowledgement of that saint, but can be used to determine your name. Each December the local M/Md les Poste sell calendars (helps as a Christmas bonus) and, amongst the local information & maps is an almanac of saints’ days. Born January 21st my middle name is likely to be Agnes, April 20th possibly Odette and I may celebrate the saints’ day as well as my birthday.
So if I really want to play the name game in France, I could be Paulin, celebrating on January the 11th,Appauline and have my day on February the 9th or Pauline (actual birthday in August) and that’s just my first name. Just might take some convincing the family that I need three gifts each year.