Wenger has just two Englishmen, Theo Walcott and Justin Hoyte, in his first-team squad - but he has refuted suggestions that English is not the common language.
"The common language is English but you cannot stop six or seven players speaking French if they are French - sometimes detrimentally to a player who is English," said Wenger.
"But I cannot stop that as I have not found any player who can express themselves better in any language but English if it is not their own. It is difficult to fight against that.
"We pay the teachers (when players arrive at the club). If I speak to the group it is in English."
And Wenger says he has sympathy for players who struggle to speak the language within a dressing room, having experienced a similar problem when in Japan with Grampus Eight.
"Don't forget I was in Japan where I understood nothing," said Wenger. "You sit there, and I know what it is not to understand what people speak about. It is good not to be paranoid!"