I search for and I think is episode 15 of the season 3. I don't remember the epsiode, I think Monica didn't know the meaning of the sentence. It was a joke Phoebe or Rachel did to her :) Oh by the way if someone don't know the meaning of " Voulez vous couchez avec moi ce soir ?" it means "Do you want to sleep with me tonight ?"
@sunnyweather both Lisa Kudrow and LeBlanc speak fluent French, and both have B.A's from major universities yet played the "dumb" characters. It is hard to play stupid and make it believable.
@friends45160 Actually, there "aux Buttes Chaumont" is more the district around the garden than the garden itself, so there are still many stores there. Moreover, the park is way older than the poster, wich according to the style might be from around the middle of the 20th century, while the park was built in the second half of the 19th century... Hope this could help, sorry my poor english...