The quietly spoken French midfielder started learning the language during his season-long stay with Premier League champions Leicester City and is again taking classes in order to keep getting better so he can improve his own game and that of his new teammates.
"I am someone a little quiet," he told Chelsea TV.
"Maybe at the beginning, but after when I know more people I am more confident. Some players here speak French and this makes me more confident and is good for the integration into the group and this is good, but also I need to speak English to help the rest of the team.
"My English is improving because I learnt it in one year at Leicester, before it was just in school and on holiday, but I have to learn more, I don't understand it all."