It happened the first time over dinner. I was saying something to my husband, who grew up in Paris where we live, and suddenly couldn’t get the word out. The culprit was the “r.” For the previous few months, I had been trying to perfect the French “r.” My failure to do so was the last marker of my Americanness, and I could only do it if I concentrated, moving the sound backward in my mouth and exhaling at the same time. Now I was saying something in English — “reheat” or “rehash” — and the “r” was refusing to come forward. The word felt like a piece of dough stuck in my throat.

Other changes began to push into my speech. I realized that when my husband spoke to me in English, I would answer him in French. My mother called, and I heard myself speaking with a French accent. Drafts of my articles were returned with an unusual number of comments from editors. Then I told a friend about a spill at the grocery store, which — the words “conveyor belt” vanishing midsentence — took place on a “supermarket treadmill.” Even back home in New York, I found my mouth puckered into the fish lips that allow for the particularly French sounds of “u,” rather than broadened into the long “ay” sounds that punctuate English.

My mother is American, and my father is French; they split up when I was about 3 months old. I grew up speaking one language exclusively with one half of my family in New York and the other language with the other in France. It’s a standard of academic literature on bilingual people that different languages bring out different aspects of the self. But these were not two different personalities but two separate lives. In one version, I was living with my mom on the Upper West Side and walking up Columbus Avenue to get to school. In the other, I was foraging for mushrooms in Alsatian forests or writing plays with my cousins and later three half-siblings, who at the time didn’t understand a word of English. The experience of either language was entirely distinct, as if I had been given two scripts with mirroring supportive casts. In each a parent, grandparents, aunts and uncles; in each, a language, a home, a Madeleine.

I moved to Paris in October 2020, on the heels of my 30th birthday. This was both a rational decision and something of a Covid-spurred dare. I had been working as a journalist and editor for several years, specializing in European politics, and had reported across Germany and Spain in those languages. I had never professionally used French, in which I was technically fluent. It seemed like a good idea to try.

When I arrived in France, however, I realized my fluency had its limitations: I hadn’t spoken French with adults who didn’t share my DNA. The cultural historian Thomas Laqueur, who grew up speaking German at home in West Virginia, had a similar experience, as the linguist Julie Sedivy notes in “Memory Speaks,” her book about language loss and relearning her childhood Czech. Sedivy cites an essay of Laqueur’s in which he describes the first time he learned that German was not, in fact, a secret family language. He and his brother had been arguing over a Popsicle in front of the grocery store near his house:

A lady came up to us and said, in German, that she would give us a nickel so that we could each have a treat of our own. I don’t remember buying a second Popsicle, but I do remember being very excited at finding someone else of our linguistic species. I rushed home with the big news.

My own introduction to speaking French as an adult was less joyous. After reaching out to sources for a different article for this magazine with little success, I showed the unanswered emails to a friend. She gently informed me that I had been yelling at everyone I hoped to interview.