MONTREAL — Is a French woman who grew up speaking the language of Molière not French enough for Quebec?

That question was being debated in Canada this week after Émilie Dubois, a 31-year-old French citizen fluent in French, was unable to get a certificate she needs to settle permanently in Quebec.

Her transgression? Writing one chapter of her doctoral thesis in English rather than in French.

Ms. Dubois would seem like an ideal immigrant for Quebec, a French-speaking province determined to preserve its French language and identity. She completed a biology doctorate at Laval University in Quebec City, a French-language university. She also started a scientific graphic design company.

But despite being a Francophone from Burgundy in eastern France, she said the immigration minister had written to her that she had not demonstrated sufficient proficiency in French to receive a certificate that is a prerequisite to gaining permanent residency.