English is a language famous for borrowing words from other tongues to bolster its own vocabulary, but often, due to a process called semantic shift or semantic change, such words end up changing their meaning from the original word, or mean something much more or less specific than the original word implied. English not only borrows words, but also accepts new meanings as they come into common usage – even if that common usage would otherwise be deemed ‘incorrect’ (e.g. the word ‘literally’ recently had its dictionary definition altered to accommodate the unenlightened people who use the term when they should be using ‘figuratively’).
French is a language English has borrowed heavily from over the centuries, and this article has a nice list of 20 words English has lifted from our cheese-loving trans-Atlantic neighbors, such as ennui, détente, panache, riposte, and savant. Adding them to your vocabulary might make you seem a tad pretentious to some, but at least you’ll be safe in the knowledge you’ll be using them correctly!