Possible Clues:

• Reply to a compliment in Calais
• "Thanks," in Toulouse
• Parisian's ''thank you''
• With 19 Across, Nice way of saying 'Thanks a lot'
• French "Thank you"
• Word of gratitude overseas
• Word of appreciation from Apollinaire
• "Thank you, Yvette!"
• Obrigado : Portuguese :: ___ : French
• '___ beaucoup!'