French phrase
Merci de répondre avant le ~ .
Meaning
Please reply by ___.
When to use it
A polite request for a reply by a stated deadline. Suitable for written requests and formal correspondence.
Example dialogue
Merci de répondre avant le lundi 10 avril.
Please reply by Monday, April 10.
Très bien, je vous répondrai avant cette date.
Very well, I'll reply by that date.