People like to stick foreign-language phrases and expressions into copy because they think it makes them appear to be intelligent and sophisticated, n’est-ce pas? And it can, except when they either don’t understand the phrase or are unable to spell it correctly.
At least once a month, I see someone who has tried to use the marvelous French verb “voilà” (“behold” or “there it is”) as an interjection to show some sort of completion. They’ve heard it in conversation, but unfortunately, they can’t spell it, so their emails, blog posts, or ads make a reference to terms such as “walla” (which is actually half of a city in Washington State).
Another common example is the Spanish “nada” (meaning “nothing”). If I had a dollar for every time I saw “notta” or some variant, I’d be able to afford a luxury vacation en España.
(Sometimes, people use inappropriate foreign words in place of perfectly good English ones. I recently saw a veteran writer use the phrase “without further adieu” when he clearly meant to say “without further ado.” “Adieu” is actually French for good-bye. Granted, his use looked prettier!)
If you’re going to use foreign phrases in your copy, please spell them correctly. And be sure that you’re using them correctly, too. You don’t have to become fluent in another language, but learning some of its basic rules will help you appear to be just as smart as you want to be.