Yesterday was Halloween. I returned home from work to find my wife (Gigi the Gorgeous) dressed as a purple goth. “Well, that’s not something you expect to see every day,” I thought to myself.

I wasn’t going to ask any questions (I’ve learned a thing or two during our 20 years of marriage), but that wasn’t an issue because Gigi told me anyway. It turned out she was representing the Lili character from the Duolingo language app as part of a Halloween challenge.

I don’t know about you, but I’m rubbish at learning other languages. I remember the tortuous sessions in the language lab at high school. Each student desk was equipped with what appeared to be a NASA-inspired control console, a microphone, and a set of ratty headphones that had perched on thousands of previous student heads.

We all sat there listening to someone waffling on about things like “La plume de ma tante” (“The pen of my aunt” or “My aunt’s pen”), repeating these mindbogglingly boring phrases into the microphone, desperately failing to replicate what we had just heard.

The teacher, who was sitting at the front of the room, had an even bigger console. You could barely see the top of her head. She could listen in on any student at will, her voice suddenly appearing in your headphones saying, “No! Say in this way…!”

All I can say is that, in the 50+ years that have passed since those days of yore, I have never once had occasion to waffle on to anyone about my aunt’s writing implements of choice in French.

Unlike your humble narrator (I pride myself on my humility), Gigi is multifaceted and multitalented. She excels at anything she turns her hand (or head) to (you should see her embroidery, for example). About a year ago, Gigi decided she wanted to learn French, so that’s what she set out to do.

After doing a little research, Gigi opted to use the free Duolingo language app, which she downloaded to her iPhone.

Gigi has been telling me all about it. She says that the app—which is free—currently supports 40 different languages. Once you’ve picked a language, the app breaks things down into quick bite-sized lessons, so you don’t get overwhelmed. Duolingo uses a combination of methods to teach reading, writing, listening, comprehension, sentence composition, and speaking skills. When you repeat a word or phrase, for example, the app immediately informs you if you’ve achieved the correct pronunciation or if you need to try again.

Duolingo uses artificial intelligence (AI) to provide a unique, self-paced teaching experience for every student. This means the same app works equally well for kids and adults. The app also uses a variety of techniques to keep students interested and engaged, such as the aforementioned Halloween challenge.

It turns out that there are several avatars who randomly interact with each student. In addition to Duo the green owl mascot itself, we have Bea, Eddy, Falstaff, Junior, Lily, Lin, Lucy, Oscar, Vikram, and Zari.

Lily is described as a “lovingly sarcastic teen” who wears only purple, including her hair. She was also one of the characters selected for the Halloween challenge. The idea was to dress like Lily and adopt a Lily-like pose, with “Extra credit for your most exasperated eye roll.”

So, how well does this work? Well, Gigi has been using this app for a run of 351 consecutive days (users are incentivized to keep their runs going). Although she’s worked with the app for only 15 to 30 minutes a day, she’s currently up to 2,063 words in French (the app keeps track, constantly reusing previously learned words to keep them fresh in your mind).

According to the Duolingo app, Gigi is at Level 51, which equates to the A2 Level of the Common European Framework of Reference for Languages (CEFR).

As an aside, thus far, in addition to her 2,063 words in French (and that was before I left home this morning), Gigi has also learned 1,251 words in Swedish, 782 words in Spanish, 300 words in Italian, 127 words in German, 40 words in Esperanto, 30 words in Hebrew, 15 words in Welsh, and 4 words in Navajo (which is four more Navajo words than I know).

All I can say is that I, for one, am very impressed. We’ve started watching the occasional TV program with both speech and captions in French. When we do this, Gigi tells me what’s going on. When we visit France (hopefully next year), I will be accompanied by my very own translator.

Gigi says that as soon as I’ve finished writing this blog, she wants me to post a link to it on Twitter at @duolingo with the hashtag #Owloween because this too is part of the challenge, so that’s just what I’m about to do…