Has anyone set a local LLM up as a language learning tool?

I've been learning German recently, and it occurred to me that I could point some of my AI horsepower at having a German speaking LLM to practice with. I'm not too concerned with the speech to text side of things or getting it to talk back, but google isn't helping much with how one would go about constructing this kind of thing to make it actually useful in terms of being a teacher.