Are there traits of Gaulish in French grammar and phonology? Hello! I'm writing a paper on the Gaulish substrate in French and apart from words of Gaulish origin I cannot find anything about this topic. I already read some books on Celtic history, French linguistics and so on but there isn't much other than Roman and Germanic invasion etc. I'd be very grateful for any idea or advise on what to look for. Is there a specific sound change? An important event? Thanks a lot in advance! (Answers in English and French are fine!)