This has been a topic I've thought about ever since I took a Teaching Company course on the History of the English Language. I got to thinking about the fact that much of the English language is French based due to the Norman conquest in 1066. Much of our legal vocabulary is of French origin (appeal, plea, justice, evidence, etc). But these words sound English to us. Others don't even though they are part of English now, like a la carte and art nouveau. What I'm wondering is what is the last French word that has been absorbed into English that no longer sounds French to us? How long does it take for a word to lose its foreignness?