A few days ago in translation class, we did an exercise on how one could express the idea "go away" in different registers of formality. The class went down the list from "Could you please excuse yourself?" to much blunter expressions. No doubt hoping to curb the rash of badly-pronounced French profanities that would ensue as soon as we walked out the door, our professor reminded us that we should be absolutely certain of our company before showing off our newfound vocabulary. The lesson actually came in handy a few days later when we needed to find an adequate translation for "to bugger" while still keeping the sentence relatively family-friendly.

My French-English dictionary indicates slang expressions by marking them with one, two or three stars. One-star expressions are things you wouldn't want to use in a formal setting — for instance, "shoot!", which apparently has a French counterpart that literally means "Wednesday!" Three-star words are ones that get movies an "R" rating when used often enough. The dictionary's system is useful but imperfect: "Bugger" gets slapped with three stars, but the French translation given right next to it gets only two.

Moreover, a dictionary can only cover so much. In any given French 1 class, a student will inevitably proclaim that he or she is excited for something — a party, a vacation — under the assumption that "excited" is a cognate. It is, in a way, but the professor will quickly point out that in French, the only party for which you can be "excité" is one going on in your pants.

For my part, I have terrible instincts about cognates: Whenever I take the time to look a word up, it's invariably a cognate; whenever I don't bother, I embarrass myself. Not long ago, I suggested to my friend that her sub sandwich would keep well in the refridgerator "because it has a lot of preservatives in it." She paused a moment before replying "I hope not, because the word you just used for 'preservatives' means 'condoms' in French."

This is what's known in French as a "false friend" — a word or expression that really seems like it should be a cognate but instead leads you to call a girl a prostitute instead of calling her "joyful." And there's no defense for them: No matter how careful you are, the odds are excellent that you'll say eventually something remarkably stupid because you assumed you knew the right word. The good news is that when it does happen, it's good for a laugh and a friendly lesson from your native-speaking friends, and you walk away no worse for wear and a little wiser. And I think that's a prospect about which we can all get a little excited.