fartsmeller

I work with modern French (my focus is on the Maghreb), so I can't speak to early modern French. However, two years of French at the undergraduate level and 9 months in France, as well as a paper drawing heavily from archival work in France and French secondary sources, did the trick. I got into my (decent) PhD program without an MA. Mind you, I also put a lottttt of time into French on my own. It was my hobby. French reading, youtube videos, speaking with natives on Italki, etc., are how I spent a lot of my time after work. I should also say that I'm a heritage speaker in Spanish, and that did help in understanding French at the structural level. 
Good luck! It's fortunately a language that has a lot of learning resources out there. 

Finalist here for  Arabic-Advanced Beginning. Any guesses as to how they decide where to send you? 

Way too much thought being put into this. The message @historygeek wrote is a fine example if you are declining. 
If you are accepting, usually you just email the department head letting them know and asking what you need to do moving forward. 

Just want to chime in and say that one should be really trying to avoid this type of behavior.  This might be a good time to practice a skill (that is, waiting patiently and unobsessively) you will need to get through grad school. There'll be times when you're waiting to hear back for (many) things but need to give your full attention to present tasks. Even if you are still being productive, it just isn't healthy to keep refreshing your e-mail (or gradcafe). Take it from someone who can get obsessive when anxious and has gotten better at avoiding this behavior.  My waiting periods have become less of an emotional rollercoaster.