Here is a Cultural Literacy worksheet on the Gallicism raison d’etre. This is a half-page worksheet with a reading of two sentences–the first a short compound separated by a colon and containing quoted material, the second a phrase giving the this term’s meaning, i.e. “reason for being.” There are three comprehension questions, the third of which asks students to compose a sentence containing raison d’etre.
Yes, I stipulate that this isn’t exactly a high frequency word in the English language. But educated people do use the word because it is useful in its place. Enough said.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.