This excites me. Everyone wants to learn a new language, no one wants to slog. But I'd pay money to play Grim Fandango, and get the chance to ask "What does Morte mean?" and have the LLM, in real-time, tutor me. And if I get bored, I can game on, business as usual.
But just give the AI a list of words I currently know, and it can slowly slip in more and more vocabulary, and maybe full sentences.