You can reply by saying "Merci" which means thank you in French.
merci monsieur.
Thank you, sir.
merci madame or monsieur
How are you, monsieur? Or more literally: you go well, monsieur?
Merci (thankyou)
merci, monsieur Collins
The cast of Merci Monsieur Robertson - 1986 includes: Suzy Falk Robert Roanne Felix Simtaine Nicolas Talalaeff Alexandre von Sivers as Robertson
You're welcome!
Merci pour votre réponse
Thankyou is of course merci, but your question may be garbled. If you mean how do you reply TO thankyou - that is, what's the French for You're Welcome, there are several forms: Je vous en prie - I beg you (not to mention it). De rien - It's nothing. C'est moi qui vous remercie - It is I who thank you.
Thank you my friend you?